To implement any software is the act of setting it up and starting to use it for the first time. Sometimes “implementation” is used in the context of a whole software program (such as a NetSuite ERP Implementation). Sometimes you will hear “implementation” applied to just a module, part, or add-on of an already-implemented software product (such as a NetSuite WMS module Implementation).
In both these cases there is a fresh, new use of a software that wasn’t present before, and therefore that software needs to be installed, accessed, turned on, configured, integrated, loaded with historical data, all of which are parts of the implementation. During an implementation, there are also things that need to happen outside the new software itself, which are often related to change management: such as understanding and documenting any business goals related to the software, educating employees on how to use the software in ways particular to their various roles, and communicating expectations to employees regarding the transition.