The algorithm is a set of mathematical, logical and sequential steps necessary to solve a problem. The algorithm was named by the name Abu Jaafar Muhammad ibn Musa al-Khwarizmi, which he invented in the ninth century AD. In Latin and European languages, the word "algorithm" was originally meant to be limited to an algorithm for only three combinations: sequence, selection and repetition.
Sequence: The algorithm is a set of sequential instructions. These instructions may be either simple or of the following two types. Selection: Some problems can not be solved in a simple sequence of instructions. You may need to test some conditions and look at the test result. Contains sequential instructions, and if wrong follow another path of instruction. This method is called decision making or selection. Duplication: When solving some problems it is necessary to repeat the same sequence of steps a number of times. This is called repetition.
It has proved that there is no need for additional structures. Using these three structures makes it easy to understand the algorithm and to discover and change the errors in it.
