Mistake and blunder are easy to understand but inaccuracy is so different, i don't have deep chess understanding to see why
Mistakes and blunders are normally a loss of material and easy to understand. An inaccuracy is therefore a loss in the evaluation due to a positional mistake. These mistakes are mostly based on the pawn position and sometimes on piece position, although a successful side attack often involves moving the pieces to that side.
Pawns structure provides for many weaknesses and some strengths. Weaknesses are doubled pawns, backward pawns, isolated pawns, weak squares caused by pawn moves (often called holes), and lack of space due to not advancing the pawns far enough. The strengths provided by pawns are the advantage of space when they are advanced (although they can become weak if advanced too far without support) and providing support for you pieces. (You learn better if you exert yourself, so the research of these concepts should be left to you.)
Since the center is the most important portion of the board, pieces are (normally) best placed when they are controlling the center or occupy the center specifically the short-range knight. The long-range pieces can affect the board from a distance, but the rook is best in four positions: 1) on open files (files with no pawns present) to invade your opponent's position, 2) on your seventh rank to harass the opponent's pawns, 3) behind pawns to support your own or harass your opponent's pawns, and 4) any position where you attack some weakness to encourage an opponent's piece to become passive/defensive.