Computers score a game in units of pawns. The score is a combination of material count and positional count. The computer tries to figure out the best sequence of moves for each side by evaluating the resulting positions at the end of the sequence. The score for the current position is the evaluation of the best play for both sides at the end of a certain depth.
Evaluation is only an estimate. As a result, which moves are best play is also an estimate.
The score will change from move to move for a few reasons. You may have made a move that wasn't the best move. This might not get a comment from the computer if it was close enough to the best move. Also, the computer can only search to a certain depth. One move later it can search one move farther, so the score estimate can chage.
What, exactly, do the plus and minus numbers mean in the computer analysis?
Where do these specific numbers come from?
Are they all my scores even if an analysis is being made of my opponent's move?
If nothing is said about a move, why does the score change?
Thank you in advance.