Question

1. What is an actor? What is their role in a system?

2. What is a walkthrough? What are the different roles played during a walk-through?

Answer 1

An actor in a computer system as defined by the Unified Modeling Language (UML) is a user which plays a certain role in the system and interacts with the subject. Actors can have many roles such as human users, external hardware, or other subjects. Actors represent many roles which are relevant to the specification or the operation of the system.
A walk-through of a system is the process which is used to assess the effectiveness of the system and also to achieve the desired results and the outcomes. A walk-through of the system can also be in the form of the peer review in which there is a team which goes through the software product and uses it and asks questions and comment about the possible errors and other problems. The different roles played during a walk-through can be a customer, user, developer, etc.