Software is in terms of relative hardware. Computer software, is in order to tell the computer to do and prepared a string of instructions the computer can understand, sometimes also called code, program. According to different functions, computer software can be roughly divided into four levels. The closest is some small computer hardware software. Them to achieve some of the most basic functions, usually "cured" in the read-only memory chip, so called firmware. 
 System software including the operating system and compiler software. System software and hardware together to provide a "platform." They manage and optimize the use of computer hardware resources. Common middleware, including database and Web servers, application software and platforms that they build a bridge between. Most types of applications, including office software, e-commerce software, communication software, industry software, game software and more. Computer software is to use various computer languages ??(also called programming language) written. The bottom is called machine language, which consists of a number of 0 and 1, can be a computer directly to understand, but hard to understand people. Top layer is called assembly language, it can only be compiled by some computer software program translated into machine language before execution. 
 Free software (Free software) is free software allows anyone to use, copy, modify, distribute (for free / small fee) software. Especially in the software's source code must be available. In a sense, "no source code, to be called a (free) software." 
 If a program is free, it can be like GNU / Linux operating system that included free. There are many ways to make a program to become free. Specifically, there are many determining factors, some listed below: free software is essentially free, non-price sale. But sometimes the software used in reference to the price "free software" the word, they mean that you may obtain a free copy of the binary code may also be purchased at your machine already contains a copy. However, this argument in GNU programs with our "free software" sense is different. 
 Since the operation, easily confused, so if software companies say that their software is free software, you must check whether you get the free software to be included in everything. Sometimes you get is free software, and sometimes not. In many languages, "free" word has two meanings: one is free, the second is free. Such as the French "libre" and "gratuit", the English "gratis" are unmistakably refers to the price (free), but did not abundantly clear that "free" meaning. This is unfortunate, because if the word, it will be very useful here.