It is a functionality of a computer science application, that entails a conversation with user and one (or more) methods of business. It is what we could call a "Process".
For example, Caso de Uso would be, within the management of clients, the discharge of a new client.
The Processes of the business are grouped, if the conversations are similar. For example, in the same Case of Use we could deal with the discharge a client, the modification of the data of a client, or its elimination. since both have many windows in common.

A case of use is defined as a set of windows. In each one of them is information and another one is requested. In the end processes are executed and we go to another window.
According to each Caso de Uso we must indicate as it is the initial window.

• you go Is the name with which Caso de Uso will be identified
• initIs the name of the window that initiates Caso de Uso.