PC - freeware - Knowledge database

Feb 4th, 2012, 8:16 am
#970107 by Zacharie
Here you will find the answer to questions from the 'freeware' topic.


Feb 4th, 2012, 8:16 am
Feb 4th, 2012, 8:32 am
#970108 by Zacharie
What is a Hosts file?

Definition
    The hosts file is a computer file used in an operating system to map hostnames to IP addresses. The hosts file is a plain-text file and is conventionally named hosts.

Purpose
    The hosts file is one of several system facilities that assists in addressing network nodes in a computer network. It is a common part of an operating system's Internet Protocol (IP) implementation, and serves the function of translating human-friendly hostnames into numeric protocol addresses, called IP addresses, that identify and locate a host in an IP network.

    In some operating systems, the hosts file content is used preferentially over other methods, such as the Domain Name System (DNS), but many systems implement name service switches (e.g., nsswitch.conf) to provide customization. Unlike the DNS, the hosts file is under the direct control of the local computer's administrator.

File content
    The hosts file contains lines of text consisting of an IP address in the first text field followed by one or more hostnames. Each field is separated by white space (blanks or tabulation characters). Comment lines may be included; they are indicated by a hash character (#) in the first position of such lines. Entirely blank lines in the file are ignored. For example, a typical hosts file may contain the following:

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    This example only contains entries for the loopback addresses of the system and their hostnames, a typical default content of the hosts file. The example illustrates that an IP address may have multiple hostnames, and that a hostname may be mapped to several IP addresses.
Feb 4th, 2012, 8:32 am
Feb 4th, 2012, 8:45 am
#970109 by Zacharie
What is a Torrent (file)?

Definition of a torrent file
    Torrent files are files under the umbrella of an extremely popular peer to peer file distribution system called BitTorrent. BitTorrent is commonly used for transferring large files within a large network of people with extremely fast download speeds. BitTorrent technology was originally developed by Bram Cohen, who came up with the protocols needed to share very large files quickly with a large group of people no matter where they were located.

Do I need special software to download torrent files?
    Yes, you do! In order to download torrents, you have to have a torrent client. A torrent client is a simple software program that manages your torrent downloads and uploads. You can find the best torrent clients on the Web by reading this article titled How to Find Torrent Clients.

Where can I find torrent files?
    There are places on the Web where you can find torrent files:

    • There are thousands of BitTorrent sites on the Web, but not all are safe, easy to use, or reputable. Find out where the good BitTorrent sites are.
    • BitTorrent search engines are able to scour the Web for torrent files in a wide variety of places, making it simple for you to find what you're looking for.

Official Legal Disclaimer for Torrent Files
    You need to know that while searching for torrents and P2P sharing technology is legal, that many of the files that you will come across on the Web are actually copyrighted. Copyright law in the United States and other countries (excluding Canada) puts these torrent files and downloading these torrent files at risk for legal action, including lawsuits. Make sure you are familiar with your local copyright laws before downloading any files.
Feb 4th, 2012, 8:45 am
Feb 4th, 2012, 11:03 am
#970123 by Zacharie
What is MySQL?

MySQL is a database system used on the web. Basically, a MySQL database allows you to create a relational database structure on a web-server somewhere in order to store data or automate procedures. If you think of it in comparison to Microsoft Access, MySQL is what holds all of your tables, PHP acts as your queries (among other things), and your forms are basically web pages with fields in them. With all of this combined, you can create truly spectacular projects on the web.
Feb 4th, 2012, 11:03 am
Feb 4th, 2012, 4:43 pm
#970191 by Zacharie
What is Norton Commander?

Norton Commander (commonly shortened to "NC") was a prototypical orthodox file manager (OFM), written by John Socha and released by Peter Norton Computing (later acquired by the Symantec corporation). NC is a file manager which provides a text user interface on top of DOS. It was officially produced by Symantec between 1986 and 1998. The last DOS version of Norton Commander, 5.51, was released on July 1, 1998.

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Feb 4th, 2012, 4:43 pm
Feb 4th, 2012, 7:12 pm
#970223 by Zacharie
What are wxWidgets?

wxWidgets (formerly wxWindows) is a widget toolkit and tools library for creating graphical user interfaces (GUIs) for cross-platform applications. wxWidgets enables a program's GUI code to compile and run on several computer platforms with minimal or no code changes. It covers systems such as Microsoft Windows, Mac OS X (Carbon and Cocoa), iOS (Cocoa Touch), Linux/Unix (X11, Motif, and GTK+), OpenVMS, OS/2 and AmigaOS. A version for embedded systems is under development.
Feb 4th, 2012, 7:12 pm
Feb 4th, 2012, 8:18 pm
#970234 by Zacharie
What are CBR/CBZ files?

A comic book archive or comic book reader file is a type of archive file for the purpose of sequential viewing of images, especially comic books. The idea was made popular by the CDisplay image viewer; since then, many viewers for different platforms have been created.

Design
    Comic book archive files mainly consist of a series of image files, typically PNG (lossless compression) or JPEG (lossy compression) files, stored as a single archive file. The file name extension indicates the archive type used:
    • .cbr → RAR
    • .cbz → ZIP

    Rare:
    • .cb7 → 7z
    • .cbt → TAR
    • .cba → ACE

Comic book archive files are not a distinct file format; only the file name extension differs from a standard file of the given archive type.

Occasionally GIF, BMP, and TIFF files are seen. The file names inside an archive are usually numbered in ascending order according to the original page number. Folders may be used to group images.

Comic book archive viewers typically offer various dedicated functions to read the content, like one page forward/backwards, go to first/last page, zoom or print. Some applications support additional tag information in the form of embedded XML files in the archive or use of the ZIP comment to store additional information. These files can include additional information like artists or story information.
Feb 4th, 2012, 8:18 pm
Feb 5th, 2012, 7:47 am
#970291 by Zacharie
What is ID3v1 - ID3v2?

The Technology:
    An MP3 tag is a generic term that describes a metadata container in an MP3 file. This information is embedded in the file structure and contains data for tags like artist, track number, album, genre, etc. This information can be used by MP3 players, media players, software players, and can also be edited using MP3 tag editors

ID3V1:
    The older ID3v1 tag which is located at the end of an MP3 file takes up 128 bytes of space. This metadata container supports up to 30 bytes for tags such as artist, album, etc.; shorter tags such as genre have a 1 byte allocation. The updated ID3v1.1 tag has an additional track number tag that the original ID3V1 doesn't.

ID3V2:
    The ID3V2 specification which was released in 1998, is a frame-based container that is located at the beginning of an MP3 file. So far, there have been 3 revisions of this specification (ID3V2.2 / ID3V2.3 / ID3V2.4). Compared to the old ID3V1 and ID3V1.1, this format is very flexible and can contain up to 256Mb of metadata (max. 16Mb per frame). Currently there are 84 different frame types - you can use some of these to embed album art, lyrics, Website addresses, and more.
Feb 5th, 2012, 7:47 am
Feb 5th, 2012, 8:24 am
#970294 by Zacharie
What is a Codec?

A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder". A codec (the program) should not be confused with a coding or compression format or standard – a format is a document (the standard), a way of storing data, while a codec is a program (an implementation) which can read or write such files. In practice, however, "codec" is sometimes used loosely to refer to formats.

A codec encodes a data stream or signal for transmission, storage or encryption, or decodes it for playback or editing. Codecs are used in videoconferencing, streaming media and video editing applications. A video camera's analog-to-digital converter (ADC) converts its analog signals into digital signals, which are then passed through a video compressor for digital transmission or storage. A receiving device then runs the signal through a video decompressor, then a digital-to-analog converter (DAC) for analog display. The term codec is also used as a generic name for a video conferencing unit.
Feb 5th, 2012, 8:24 am
Feb 5th, 2012, 9:24 am
#970305 by Zacharie
What are "jitter" and "jitter correction"?

The first thing to know is that there are two kinds of jitter that relate to audio CDs. The usual meaning of "jitter" refers to a time-base error when digital samples are converted back to an analog signal. The other form of "jitter" is used in the context of digital audio extraction from CDs. This kind of "jitter" causes extracted audio samples to be doubled-up or skipped entirely. (Some people will correctly point out that the latter usage is an abuse of the term "jitter", but we seem to be stuck with it.)

"Jitter correction", in both senses of the word, is the process of compensating for jitter and restoring the audio to its intended form. This section is concerned with the (incorrect use of) "jitter" in the context of digital audio extraction.
Feb 5th, 2012, 9:24 am
Feb 5th, 2012, 10:34 am
#970337 by Zacharie
What is a Beta version?

Beta (named after the second letter of the Greek alphabet) is the software development phase following alpha. It generally begins when the software is feature complete. Software in the beta phase will generally have many more bugs in it than completed software, as well as speed/performance issues. The focus of beta testing is reducing impacts to users, often incorporating usability testing. The process of delivering a beta version to the users is called beta release and this is typically the first time that the software is available outside of the organization that developed it.

The users of a beta version are called beta testers. They are usually customers or prospective customers of the organization that develops the software, willing to test the software without charge, often receiving the final software free of charge or for a reduced price.

Beta version software is often useful for demonstrations and previews within an organization and to prospective customers. Some developers refer to this stage as a preview, prototype, technical preview (TP), or early access.

Some software is kept in perpetual beta—where new features and functionality is continually added to the software without establishing a firm "final" release.
Feb 5th, 2012, 10:34 am
Feb 5th, 2012, 4:15 pm
#970631 by Zacharie
What is the 'recycle bin'?

In computing, the trash (also known as the recycle bin and by other names) is temporary storage for files that have been deleted in a file manager by the user, but not yet permanently erased from the physical media. Typically, a recycle bin is presented as a special file directory to the user (whether or not it is actually a single directory depends on the implementation), allowing the user to browse deleted files, undelete those that were deleted by mistake, or delete them permanently (either one by one, or by the "Empty Trash" function).

Within a trash folder, a record is kept of each file and/or directory's original location. On certain operating systems, files must be moved out of the trash before they can be accessed again.

Whether or not files deleted by a program go to the recycle bin depends on its level of integration with a particular desktop environment and its function. Low-level utilities usually bypass this layer entirely and delete files immediately. A program that includes file manager functionality may or may not send files to the recycle bin, or it may allow the user to choose between these options.
Feb 5th, 2012, 4:15 pm
Feb 5th, 2012, 4:22 pm
#970638 by Zacharie
What are Cookies?

A cookie, also known as an HTTP cookie, web cookie, or browser cookie, is used for an origin website to send state information to a user's browser and for the browser to return the state information to the origin site. The state information can be used for authentication, identification of a user session, user's preferences, shopping cart contents, or anything else that can be accomplished through storing text data on the user's computer.

Cookies cannot be programmed, cannot carry viruses, and cannot install malware on the host computer. However, they can be used by spyware to track user's browsing activities—a major privacy concern that prompted European and US law makers to take action. Cookie data can also be illicitly disclosed by hackers to gain access to a victim's web account.
Feb 5th, 2012, 4:22 pm
Feb 5th, 2012, 4:27 pm
#970646 by Zacharie
What is a Spyware?

Spyware is a type of malware (malicious software) installed on computers that collects information about users without their knowledge. The presence of spyware is typically hidden from the user and can be difficult to detect. Typically, spyware is secretly installed on the user's personal computer. Sometimes, however, spywares such as keyloggers are installed by the owner of a shared, corporate, or public computer on purpose in order to secretly monitor other users.

While the term spyware suggests software that secretly monitors the user's computing, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, such as Internet surfing habits and sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software and redirecting Web browser activity. Spyware is known to change computer settings, resulting in slow connection speeds, different home pages, and/or loss of Internet connection or functionality of other programs. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is provided by the term privacy-invasive software.

In response to the emergence of spyware, a small industry has sprung up dealing in anti-spyware software. Running anti-spyware software has become a widely recognized element of computer security practices for computers, especially those running Microsoft Windows. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is surreptitiously installed to control a user's computer.
Feb 5th, 2012, 4:27 pm
Feb 5th, 2012, 4:30 pm
#970649 by Zacharie
What are pop-ups?

Pop-up ads or pop-ups are a form of online advertising on the World Wide Web intended to attract web traffic or capture email addresses. Pop-ups are generally new web browser windows to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well.

A variation on the pop-up window is the pop-under advertisement, which opens a new browser window hidden under the active window. Pop-unders do not interrupt the user immediately and are not seen until the covering window is closed, making it more difficult to determine which web site opened them.
Feb 5th, 2012, 4:30 pm