This is week number 2 of the course. In week number 2, we'll talk about computer software. So what is computer software? A computer software is basically a set of instructions telling your computer to do something for you, which is also known as computer programs. Unlike hardware components which have something that you can physically see and touch, software is just a set of instructions, which are intangible. Without software, a computer is actually useless. If we refer to this picture of a computer system, basically all the applications that we use on pop off an operating system, they are all software, and the operating system itself is also a piece of software, and other device drivers that we used to drive hardware components, they are all software. So basically, these are all the software that we have on a computer system. Software is everywhere. Microsoft Windows is a piece of software, Microsoft Excel is also a piece of software. Google Chrome, which is your browser is also a piece of software. GIMP, which we are going to use for image manipulation is another piece of software. We can categorize computer software into three different types: system software, programming software, and also application software. In this module, we will talk about this three types of software one by one.