Manual testing is performed by someone who interacts with an application by clicking and checking the application programming interface using special tools, such as Charles (https://www.charlesproxy.com/). This tool is a proxy that makes it possible to view all HTTP and HTTPS traffic between a client application and a server.

The main window of this tool looks as follows:

Manual testing is expensive as it requires a qualified person and a configured environment. We should also take into account human errors, since a tester can omit some steps and conditions.