(i) Trade discount is a deduction given by the supplier to the buyer on the list price or catalogue price of the goods
(ii) It is given as a trade practice or when goods are purchased in large quantities. It is shown as a deduction in the invoice.
(iii) Trade discount is not recorded in the books of accounts. Only the net amount is recorded.

(i) A three column cash book includes three amount columns on both sides, i.e., cash, discount and bank, This cash book is prepared in the same way as simple and double column cash books are prepared.
(ii) Opening balance, cash deposited into bank, cheque deposited in the bank appear in the bank column on the debit side of the three column cash book.
(iii) All the transactions which decrease bank balance are recorded in the bank column on the credit side

(i) Double column Cash book is a cash book with cash and discount columns. As there are two columns, i.e., discount and cash columns, both on debit and credit sides, the cash book is known as 'double column cash book'.
(ii) The double column cash book is prepared on the lines of simple cash book. It has only one additional column, i.e., discount column on each side.

(i) Single column cash book has only one amount column, i.e., cash column. Only cash transactions are recorded in this book.
(ii) All cash receipts and payments are recorded systematically in this book.

(i) Cash book is the book in which only cash transactions are recorded. Cash receipts are recorded in the debit side while cash payments are recorded in the credit side.
(ii) The cash book is the book of original entry or prime entry.