Each chess piece is identified by an initial letter. Most players use K for king, Q for queen, R for rook, B for bishop, N for knight, and P for pawn. (Spanish speakers use R for king, D for queen, T for rook, A for bishop, C for knight, and P for pawn.)
Each player has two knights, two bishops, and two rooks; and it is often necessary to distinguish between them. The pieces starting on the queen's side of the chessboard (left for white, right for black) can be specified as the 'queen's rook', 'queen's knight' and 'queen's bishop'. Similarly, the pieces on the king's side (right for white, left for black) are the 'king's rook', 'king's knight' and 'king's bishop'. They can be abbreviated QR, QN, QB, KR, KN, and KB.
How you refer to a square depends on your perspective as either the black or white player. The ranks (rows) are numbered from 1 to 8. Your first rank is the row closest to you; your eighth rank is the row farthest from you. (Your pawns start on your second rank; your major pieces start on your first rank.)
Each file is named after the piece you have there at the start of the game. Thus the column that your queen starts in is called the queen's file, and is labeled 'Q'. The king's file is named 'K', and so on.
Thus each square has two names, one name from white's point of view and another from black's. From white's perspective, the white queen starts on square Q1; but from black's perspective, the white queen starts on Q8. The square nearest white's left hand is called "queen's rook 1" (QR1) by white, but "queen's rook 8" (QR8) by black.
(In Spanish descriptive notation, the rank comes first. So the Spanish king starts on 1R, not R1.)
An ordinary move is represented by the piece's name, a hyphen, and its destination square. For example: P-K4 would be read as "pawn to king 4," and N-QB3 would be read as "knight to queen's bishop 3."
A move with capture is represented by the piece's name, an x, and the name of the piece captured. For example, QxN would be read as "queen takes knight."
Typically, only enough information is recorded to make the move unambiguous. A pawn capturing a pawn would be recorded as PxP if there is only one way for any pawn to capture another, or as BPxP if only one of the player's Bishop's Pawns can capture another pawn, or as PxQBP, or other such variations.
As a last resort, the location of a capture or of the starting point of a move may also be shown, delimited with parentheses. For example: BxN(QR6) if the bishop had its choice of knights to capture; or R(R3)-Q3 if either of the player's rooks could have moved to square Q3. Sometimes only the rank or file is indicated, as R(6)xN.
Parentheses are also used to indicate promotion. For example: P-R8(Q). 0-0 is used to record a king-side castle and 0-0-0 for a queen-side castle. Special indicators are appended to a move to indicate en passant (e.p.) and check (+ or Ch); and the words Mate (or Checkmate), Resign, and Draw are appended when appropriate.
When listing the moves of a game, first the move number is written, then
the move by white, followed by the move by black. For example:
1. P-K4 P-K4
2. P-Q4 PxP
(In Spanish descriptive notation, since the rank comes first it can serve as a separator; so the hyphen is not needed. So the Sicilian opening would be written 1. P4R P4AD.)
By identifying each square with reference to the player on move, descriptive notation better reflects the symmetry of the game's starting position. For example, one can say: "Both players opened with P-K4 and planned to play B-KN2 as soon as possible." The maxim that a pawn on the 7th is worth two on the 5th makes sense from both Black's perspective as well as White's perspective. Also, because the pieces captured are named, it is easy to skim over a game record and see which ones have been taken at any particular point.
People might become confused because each square has two different names. On average, abbreviated algebraic notation represents the same moves with fewer characters. Algebraic chess notation is now the lingua franca of chess notation.