it is used to measure the complexity of software process& it
is used to measure how many test cases are passed in the
application

Cyclomatic Complexity is a software measurement developed 
by Thomas Macabe. It directly measures linearly independent 
path of program source code

Cyclomatic Complexity = No of Edges - No of Nodes + 2 * 
Number of connected components

or alternative Definition G = Edges - Nodes + 2

or No of closed loops in the flowgraph + 1

Cyclometric complexity is a whitebox testing technique 
(More useful when doing Unit testing). In this we try to 
identify all possible unique program branches (if, while, 
forloops etc.) and ensure our test suit is covering these 
all possible branches at least once.