week3

On week 3, we have learnt about the role of computer software. Firstly, we were introduced 3 types of software. There are System software, application software and programming language.

And also we learnt about Software Layer. It involved in the user-computer interaction. 

The above explanation describes the common software layers of a computer. An application may communicate with the operating system through a piece of software called a DLL (Dynamic Link Library.) Most operating systems have a command line interface that lets users communicate more directly with the operating system and with hardware devices through the BIOS.The important thing to On week 3, I have learnt about software. In my opinion, it is really hard to remember and distinguish understand is that your computer has layers of software. You should understand where each layer resides in the path from user to hardware. You should now understand that when you dial out with your web browser, the request is passed to the operating system, which passes it to the modem driver, which communicates with BIOS on the modem. Those BIOS is the program that actually works the electronics of your modem. From this, I knew how hardware depends on software.

 Then, I moved to know about system software. There are 2 types: operating systems and Utility programs.

 Operating systems have 3 types:  

         _Stand-alone OS_ a complete OS on a computer. Ex: windows, DOS, Mac OS, UNIX, Linux.

           _Server OS. Ex: Windows NT, UNIX..

         _Embedded OS. Ex: Windows CE, Palm OS..

Unility programs: most OS include some built-in utility programs, but most users buy additional program to improve the functions.
IN SESSION 2: we learnt clearly another type of software. It was Programming Language( a set of words, abbreviations, and symbols that enables a programmer to communicate instructions to a computer). There are 2 types: Low-level language and High-level language. However, in HLL, there are various types and characteristics especially the object-oriented based languages. Some HLL types: Procedural, functional, object-oriented, rule-based.
In SESSION 3: it was about the last type of software. It was application software. It was really very interesting to learn. Some categories of application software: commercial software, shareware, freeware, public domain software and others.