What is Accounting Information System?

Legal Definition
An accounting information system (AIS) is a system of collecting, storing and processing financial and accounting data that are 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 financial reports can be used internally by management or externally by other interested parties including investors, creditors and tax authorities. Accounting information systems are designed to support all accounting functions and activities including auditing, financial accounting & reporting, managerial/ management accounting and tax. The most widely adopted accounting information systems are auditing and financial reporting modules.
-- Wikipedia
Legal Definition
The system responsible for creating financial reports for both internal and externa parties.