q describe big notationbig o notation the set o

Question

Q. Describe Big Notation?

Big O Notation: The set O (g(n)) comprises all functions f(n) for that there exists   positive constants c such that for satisfactorily large values of n we have 0<= f(n) <= c*g(n). In another words,

O (g(n)) ={ 0<= f(n) <= c*g(n) for all n >= n_o }