Requirement Analysis 
High level design
low level design 
construction & unit testing
system and integration testing
Acceptance 
maintance

Software development life cycle consists of four phases.
That is,
1.Analysis
2.Design
3.Implementation and
4.Testing

1.Analysis: Define the goals.Gathering the requirements to 
develope a software for customer satisfaction.Aanalyse that 
how to use and design?.

2.Design: Detailed design the requirements as a structure.

3.Implementation: Implement the detailed design with 
designed code.

4.Testing: Check the whether the software will work 
properly or satisfies the customer expectation.
If it is satisfies the customer needs, that software 
properly produced.

This is software development life cycle.