DIY stands for Do it yourself. This acronym is used when you want to show that there is no need for experts or professional or special training in building, modifying, or repairing something. So, Do-it-yourself tasks are the tasks that you can do yourself, rather than taking help of professionals and even without specialized training.
Similarly, when you make something yourself rather than buying it ready-made or paying someone else to make it, it will be a Do-it-yourself task. So, in simple words, we can say that it is an activity in which you do something yourself without involving others. In the same way, in technology, the do-it-yourself technique enables you to develop products without the help of an expert or an organization.