Before directly jumping deeply in c++, let's first start by creating the roots of computer science. In this post we will answer the following question. What is Computer and How it works? What is Program and Operating system? Low Level vs High Level Language? Compiler v/s Interpreter? By Knowing All these basic concepts You will be able to understand the upcoming more complex concepts easily. Let's start answering the above questions. What is Computer and How it works? What is computer? If I answer briefly, what is computer? then it is just a calculator used for doing simple calculations. If I have to answer where is computer used?, then I could probably say everywhere. We are surrounded by computer, for example mobile, smartwatches, and personal computer (obviously). The below image is the first mechanical computer that we used for calculation. Abacus How computer works? The computer's internal functionality is a whole separate bra