When working on a large project you will have to find a way to coordinate the work effort so each person contributing to the delivery has a system of rules to follow that makes it possible to have multiple people working together at the same time.
At the time of writing this document agile development is the main work process for most companies.
You can read more about agile development here.
At the time of writing this document the waterfall method is a bit outdated but the concepts in the method can still be found in many companies.
You can read more about waterfall development here.
Continuous integration or CI is the process of having a delivery strategy that allows developers to deploy code on a frequent basis.
You can read more about CI here.
At the time of writing this document the following tools are very common to find in IT companies.