Hi colleagues in the forum,
There is great difference between explaining something and handing out instruction. The difference is that when you are explaining anything, you are actually breaking the issue down to the understanding of the person involved. For instance, a father would like his child to explain why he/she (the child) was rusticated from school. This means that the father wants the child to tell him in detail why he/she was rusticated - give the reasons that led to the action against the child by the school. Again, you might want your friend to explain the use of an apparatus that you have found in his/her house, which you have not seen or used before. In this case, you want your friend to tell you what that apparatus is used for and how it is used.
In the case of handing out instruction, you are merely telling somebody to do something. If our English Teacher tells us to read a passage and answer the questions that follow, it is an instruction. He can as well tell us to visit a library and get a particular information for him. This is also an instruction handed out by the Teacher.