For example the Sierra Corporation and accounting system use accounts. There are individual accounting record of increases and decreases in a specific asset, liability, stockholders equity, and revenue or expense items. They have separate accounts for cash accounts payable service revenue the expense so alignment and resembles the letter. Accounting has terms and debt one the left is accounts and the right side is credit this is the short term is Dr and Cr. It is not for increase or decrease these are terms they use for short for debit and credit. The two sides can not exceed the credit amount show no matter what happens.

Debit Credit
-5,000 10,000
-900 5,000
-600 1,200
-500 10,000
-4,000 5,000 900 600 500 4,000 10,000 5,000 1.200