Answer :
Final answer:
A box on the lifeline in Unified Modelling Language (UML) represents the activation of an instance, meaning a specific object is active and controls the program flow during the time the box shows. The start and end of the box indicate when the object begins and ends its control.
Explanation:
In the context of sequence diagrams in Unified Modelling Language (UML), a box sitting on top of the lifeline represents the activation of an instance. This means that a particular object is active and controlling the flow of the program during the time period the box appears on its lifeline. The start and end of the box mark the time when the object begins and ends its active control over the process.
For example, in a sequence diagram showing the interaction between different objects in a program, a box on the lifeline of a 'User' object might denote the period where the User is entering their username and password to log into a system. Once the User has submitted the data, the box will end on the lifeline, indicating that the User object is no longer controlling the process.
Learn more about Lifeline Activation in UML here:
https://brainly.com/question/36467828
#SPJ11
