The modern meaning for algorithm is quite similar to that of recipe, process, method, technique, procedure, routine, rigmarole, except that the word "algorithm" connotes something just a little different. Besides merely being a finite set of rules that gives a sequence of operations for solving a specific type of problem, an algorithm has five important features:

1)Finittness.

2)Definiteness.

3)Input.

4)Output.

5)Effectiveness.

Performance analysis: machine independent

1)Complexity theory
   Space complexity: amount of memory --> a)fixed space(instruction, simple variables, constants). b)memory depends on instance.
   Time complexity: amount of computer time --> a)compile time. b)execution time depends on instance.

Performance measurement: machine dependent

 1)Asympototic Notation --> Big "Oh"