An Equivalence Partition is a subset of input values expected to be treated similarly by a system. It is used in software testing to reduce the number of test cases.
Key Aspects:
1. Group similar inputs
2. Represent a range of values
3. Based on system specifications
4. Assume uniform behaviour within the partition
5. Help identify test cases
Benefits:
1. Reduce the number of test cases
2. Improve test coverage
3. Identify boundary conditions
4. Streamline test design process
5. Focus testing on representative values
Testers typically identify equivalence partitions during test design. They then select representative values from each partition for testing.