General chess terms

Every general term, defined and illustrated.

General
Center
The center in chess refers to the four central squares of the board — e4, d4, e5, and d5 — as well as the surrounding squares that form what is known as the extended center (c3, c4, c5, c6, d3, d6, e3, e6, f3, f4, f5, f6).
General
Chessboard
The chessboard is the playing surface on which a chess game takes place: it consists of 64 squares arranged in an 8×8 grid, with alternating light and dark squares.
General
Diagonal
A diagonal in chess is a line of same colored squares running at an angle across the board, along which bishops and queens move.
General
FEN
FEN (Forsyth Edwards Notation) is a standardized text format that describes a complete chess position in a single line of text.
General
File
A file is a vertical line on the chessboard, connecting all squares that share the same letter from rank 1 to rank 8.
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Flank
In chess, the flank refers to either of the two lateral halves of the board: the kingside (files e through h) or the queenside (files a through d).
General
Kingside
The kingside refers to the right half of the chessboard from White’s perspective — the f, g, and h files (and often the e file depending on context) — the side where the white king starts the game and where the short castle (O O) shelters it behind a pawn barrier.
General
Move
A move in chess is the action of transferring a piece from one square to another according to the rules of the game, making it the fundamental unit of every chess game.
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Online rapid
Online rapid chess is a format played on the internet with a time control typically ranging from 10 to 30 minutes per player for the entire game.
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PGN
PGN (Portable Game Notation) is a standardized text format used to record and share chess games, capturing both the moves played and key game information such as players' names, date, and result.
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Post-mortem analysis
Post mortem analysis is the critical review of a chess game carried out after it has ended, with the goal of identifying mistakes, missed opportunities, and key turning points.
General
Queenside
The queenside refers to the left half of the chessboard from White’s perspective, covering the a, b, c, and d files — the side where the queen starts the game.
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Rank
A rank, in chess, is a horizontal row of the chessboard, consisting of eight squares running from left to right.
General
Time trouble
Time trouble refers to the critical situation where a player is running dangerously low on the clock, to the point where time management becomes as decisive as the quality of the moves played.
General
Turn to move
"Having the move" — in French, le trait — means it is your turn to move a piece on the board.