If you are asking 'what does crossing a cheque mean?', it means that two parallel lines, about 2 centimetres apart, are written across the middle of the cheque, from top to bottom. . Writing " Account payee" or " A/C payee" between the lines does as explained by 4candles It means that the cheque can only be paid into the account of the person named on it.
Writing the two lines without 'account payee' means that the cheque must be paid into a bank but can be paid into anyone's account , with the consent of the person named on it. A cheque with no lines on can be exchanged, by the person named on it , for cash at a bank without being paid into a bank account..