In the/somebody’s way
Definition 1 of 2
Pro Tip 1/3Physical Obstacle
Used when something literally blocks your path or space. 
I can't get to the window because your chair is in the way.
Pro Tip 2/3Politely Move
It's a courteous way to ask someone to move without being rude. 
Excuse me, you're in the way, could you please step aside?
Pro Tip 3/3Visual Blocking
It emphasises that someone's view is being obstructed. 
I can't see the board; the pillar is in the way.