Most projects are a team effort. The team could be located in different places or in the same place, and members from different locations have to work in sync mode so their changes won't conflict with other team members. A system won't mature until it is used in various scenarios; these scenarios could be based on the experience of domain experts or come from the production environment. There is a chance that a system could crash in the production environment even if the system is regarded as a perfect system. In terms of web applications, the conditions are more critical due to performance glitches, bad user experiences, and so on. A system should go through a process where, if a team member makes changes, the code is integrated after unit tests and the build is then deployed in the related environment.
When we say deployment...