Copywriting is the writing of text for the purpose of advertising or other forms of marketing. The product, called copy or sales copy, is written content that aims to increase brand awareness and ultimately persuade a person or group to take a particular action, usually to become a customer. If the person is already a customer, ideally they will be persuaded to buy more stuff.
Web development can be an ongoing process, from initial requirements gathering, where the needs of the client are understood, a specification is agreed and then the coding completed. However, that is not the end of the story. The coding team will test the software, and once satisfied, they will pass it on to the in house testing team. Once the software supplier is happy, they deliver the software to the client and they test it. Once they are happy that everything looks as it should, and works as it should, the software is moved live. Depending on contracts used, there may be a support agreement in place that obligates the software supplier to fix any bugs found post delivery.
Commissioning a web development project, and having it delivered to a live environment is all well and good, but how do your employees know how to use the software. Without the proper documentation of functionality, they will be groping in the dark, and will potentially do untold damage. The software needs documentation that explains every piece of functionality. The flow of control through the task cycle of a function should be explained clearly so that new employees can read the user guide and be confident they know how to use the software.
Training works hand in hand with documentation. Trainers can teach users of the software how to get the most out of it and then documentation can be referred to afterwards, when the trainer is no longer there. Training can be geared towards the unique needs of each client, and doesn't need to use a one size fits all approach.