"Free software refers to software that users have the freedom to run, adapt, distribute, and make improvements on with only one restriction: the redistributed software versions must contain the original terms and stipulations of free use, referred to as copylef"..
Richard Stallman started widely using the phrase in the 1980s when he was running the Free Software Foundation (established to support development of free software) and the GNU Project (established to develop a free operating system).
The Free Software Foundation (FSF) developed four principles, dubbed the “four essential freedoms,” that software must abide by in order to be considered free software:
- The freedom to run the program and use it for any purpose;
- The freedom to study the program, including how it works, and modify it to meet your preferences and needs;
- The freedom to freely redistribute the program to better help others; and
- The freedom to redistribute freely any copies of your modified and adapted versions of the program to better help others.
2.Open Source Software ?
"The meaning of “open source” closely resembles “free software,” but it
is not identical to it. Basically, open source refers to a software with
a publicly accessible source code under a license that gives users the
right to do with the software as they please, including studying,
changing, and distributing it".
The term, open source, was originally coined in the late 1990s by individuals—the founders of the Open Source Initiative (OSI)—seeking a less ambiguous definition of free software.
Although the OSI agreed with the FSF about development and distribution of free software, they emphasized that software freedom was mainly a practical matter and not just an ideological one. Therefore, in a slight shift from free software, open source software emphasizes pragmatism in use, particularly in security, cost savings, and transparency. Open source supporters intended to concentrate on the practical advantages of using open source software that would be more appealing for a corporate world, instead of emphasizing ethics and morals.
For example, while Chrome OS and Android are open source projects, they cannot be categorized under free software because they do not sufficiently meet all the four essential freedom conditions.
Eventually, it can be said that both open source and free software definitions refer to developing the same type of software, but the difference lies on the messaging used.
3.FreeWare Software ?
Contrary to free software and open source software, freeware fails to
focus on freedom, and it also lacks an explicit definition. Generally,
freeware refers to software that is available without demanding a fee
for usage. Freeware software can be distributed as a fully operational
program for an unlimited period.
The rights of owning such a software usually belongs wholly to its developer. In some cases, the developer may choose to require users to start paying for the freeware after a certain period. Unlike free software and open source software, freeware is normally shared without including its source code. Therefore, users are unable to make any changes to it.
Examples of freeware are widespread, but two common examples are Adobe Reader and Skype; both programs are available for free, but neither is open source, and both are proprietary. Another example of common freeware might be an old game, which a game developer might choose to re-release as freeware. Though this means the game is now available free of cost, but the code behind the game remains unavailable and proprietarily protected.
The rights of owning such a software usually belongs wholly to its developer. In some cases, the developer may choose to require users to start paying for the freeware after a certain period. Unlike free software and open source software, freeware is normally shared without including its source code. Therefore, users are unable to make any changes to it.
Examples of freeware are widespread, but two common examples are Adobe Reader and Skype; both programs are available for free, but neither is open source, and both are proprietary. Another example of common freeware might be an old game, which a game developer might choose to re-release as freeware. Though this means the game is now available free of cost, but the code behind the game remains unavailable and proprietarily protected.
4. ShareWare Software ?
The concept of shareware is similar to that of freeware in that it is
originally distributed free of charge. However, unlike freeware, that
cost-free period is usually only for a trial period, after which the
software stops being freely available until the user pays for continued
use or license. Other versions of shareware may be functional for an
indefinite trial period, but certain features are unavailable without
paying for their use.