Computer programs usually execute some algorithm. Algorithms are a sequence ot steps, necessary for the completion of a certain task and for gaining some expected result, something like a "recipe". For example, if we fry eggs, we follow some recipe (an algorithm): we warm up the oil in a pan, break the eggs inside it, wait for them to fry and move them away from the stove. Analogically, in programming the computer programs execute algorithms: a sequence of commands, necessary for the completion of a certain task. For example, to order a sequence of numbers in an increasing order, an algorithm is needed, in order to find the smallest number and print it, then find the smallest number amongst the rest and print it and this is repeated until there are no more numbers.
For convinience when creating programs, for writing programming code, for execution of programs and other operations related to programming, we need a development environment, for example Visual Studio.