Defination of Accounting Information Systems (AIS)

The collection, storage and processing of financial and accounting data that is used by decision makers. An accounting information system is generally a computer-based method for tracking accounting activity in conjunction with information technology resources. The resulting statistical reports can be used internally by management or externally by other interested parties including investors, creditors and tax authorities.

Investopedia Says:
An accounting information systems that combines traditional accounting practices such as the Generally Accepted Accounting Principles (GAAP) with modern information technology resources. Six elements compose the typical accounting information system:      

• People - the system users.
• Procedure and Instructions - methods for retrieving and processing data.
• Data - information pertinent to the organization's business practices.
     
• Software - computer programs used to process data.
      
• Information Technology Infrastructure - hardware used to operate the system.
• Internal Controls - security measures to protect sensitive data.

An accounting information system (AIS) is a system.

Accounting information systems are composed of six main components:^[1]

1. People: users who operate on the systems
2. Procedures and instructions: processes involved in collecting, managing and storing the data
3. Data: data that is related to the organization and its business processes
4. Software: application that processes the data
5. Information technology infrastructure: the actual physical devices and systems that allows the AIS to operate and perform its functions
6. Internal controls and security measures: what is implemented to safeguard the data