The current object is that object where the helpers are located. This is the object where all the action would be directed to, in case you do not have a selection set. If you do have a selection set; for some commands, this object would still be the reference object on which TAD would do the internal calculations (such as shifting a set of objects)

Sometimes it is important to know that there are no objects that are selected; and you want actions to go ONLY on this current object. If that is what you want to do; take a glance at the selection count that is noted in a small box below the information tab (That is usually seen on the left side of the screen) There, the selection should be ZERO – then you are sure that nowhere else were there any selections

Clever Hint
If you have a selection set in place; and yet you want TAD to focus on the current object itself (temporarily ignoring the set), then you should click on the checkbox tucked in the selection toolbar – if ticked, TAD will temporarily forget that there was a selection set and all edit action will be directed to the current object only