Appium is an open source, cross-platform automation testing tool. It is used for automating test cases for native, hybrid and web applications. The tool has a major focus on both Android and iOS apps and was only restricted to the mobile application testing domain.
Working:
The client communicates to the server using a session. Using objects the key elements of the communication process are sent. Communication is handled by the mobile JSON Wire Protocol. The server differentiates between an iOS request and an Android request using the desiredCapabilites arguments. Appium server then processes the request to the respective UI Automators. The results of the test session are then communicated to the server and then back to the client system in terms of logs, using the mobile JSON Wire Protocol.