'this side' - a way to describe the position of something or someone, relative to something/one else.
eg This is James this side of another person. The person I refer to is positioned in that place relative to something or someone.
However, I could also say 'That is James ...' because he might be some distance away from me.
'at your end'
This is another expression to do with position or location, but it doesn't have to mean a physical location.
The problem is at your end - I won't take responsibility for finding out what is wrong.
Student or Learner