Intro to Programming 1

The introduction to computer science Wikiversity course if obviously very underdeveloped so I went on with the 'Introduction to Programming'' hoping it won't suffer the same issues...

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A program is a set of instructions that tell a computer how to do a task. When a computer follows the instructions in a program, we say it executes the program. You can think of it like a recipe that tells you how to make a peanut butter sandwich. In this model, you are the computer, making a sandwich is the task, and the recipe is the program that tells you how to execute the task.

• Activity: Come up with a set of instructions to tell someone how to make a peanut butter sandwich. Don't leave any steps out, or put them in the wrong order.

Was that easy? Did you remember all the steps? Maybe you forgot to tell me to use a knife to spread the peanut butter. Now I've got peanut butter all over my hands! Of course, you say, a person wouldn't be that dumb. But a computer is that dumb. A computer will only do what you tell it to do. This might make programming frustrating at first, but it's relieving in a way: if you do everything right, you know exactly what the computer is going to do, because you told it.

Of course, computers don't understand recipes written on paper. Computers are machines, and at the most basic level, they are a collection of switches—where 1 represents "on" and 0 represents "off". Everything that a computer does is implemented in this most basic of all numbering systems—binary. If you really wanted to tell a computer what to do directly, you'd have to talk to it in binary, giving it coded sets of 1s and 0s that tell it which instructions to execute. However, this is nearly impossible. In practice, we use a programming language.