When you launch a program, there is an initial setup that the program has to go through to be ready. A program has numbers, characters, words, pictures, graphics, etc, that are part of the application. As these things are numerous, so is the size of the program, and so is the length of time needed to come up. Your job as a programmer is to write instructions that can make such programs available to the computer and usable to people who want to interact with the machine.
To write your programs, you will be using alphabetic characters that are a, b, c, d,
e, f, g, h, I, j, k, l, m, n, o, p, q, r, s, t, v, w, x, y, z, A,B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z. You will also use numeric symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Additionally, you will use symbols that are not easily readable but are part of the common language; they are ` ~ ! @ # $ % ^ & * ( ) _ + - = : “ < > ; ‘ , . /. Some of these symbols are used in the Object Pascal language while some others are not. When creating your programs, you will be combining letters and/or symbols to create English words or language instructions.
Some of the instructions you will give to the computer would consist of counting the number of oranges, converting water to soup, or making sure that a date occurs after January 15. After you have typed an instruction, the compiler would translate it to machine language. This is because the computer does not understand the language you and I speak or write. The computer represents any of your instructions as a group of numbers. Even if you ask the computer to use an orange, it would translate it into a set of numbers. As you give more instructions or create more words, the computer stores them in the computer memory using a certain amount of space for each instruction or each item you use.
There are three numbering systems that will be involved in your programs, with or without your intervention. The decimal system provides the counting techniques that you use everyday. The hexadecimal system is an intermediary system that allows you to know how the computer deals with numbers. The binary system is the actual system that the computer uses to find out (almost) everything in your program.