SDLC

The phases of the software development life cycle

are which describes how to develop, maintain particular software.
The life cycle aims to develop a good quality product/software.
High quality, lowest cost in short time.

Requirement Phase : most critical phase, SRS (Software Requirement Specification) is a detailed description of softwares' requirements

Design Phase : Logical to physical designing.

Build/Development Phase : Coding, longest phase.

Testing Phase : try it before deploy.

Deployment/Delivering Phase : except critical one, defects' solution waits for the next version.

Maintenance : maintain its operational effectiveness