Let's imagine you use Skype as the platform to give students lessons. Some students' first time using Skype happens during their English lesson.They might not know how to find the button to display the chat box, or they can't immediately find audio / microphone controls, or they don't know how to share their screens.
Imagine one of your students has one of these problems, but s/he can't figure out how to explain the problem to you.
How likely are you to have the patience to guess, anticipate and ask questions to determine the problem, and then explain to him or her how to fix that problem?