Game analysis
Inaccuracy
An inaccuracy misses a stronger opportunity or slightly worsens the position without necessarily losing material immediately. The boundaries between inaccuracy, mistake and blunder depend on the platform. A weaker move may also be easier to play in practice than a difficult engine line.
A practical example
You defend a pawn passively when an active rook move could defend it while occupying an open file. No material is lost immediately, but your pieces remain less coordinated.
A common mistake
Treating every small evaluation change as equally important. A difficult only move deserves different training attention from an obvious improvement that repeatedly occurs in your games.
Try this in your next review
Compare your move with the stronger alternative: which piece becomes more active, which weakness appears and which plan becomes possible? Write a reusable decision rule rather than just recording a move number.