Interpretation is verbal. A good interpreter may not be a good translator, and vice versa. It is the difference between writing and speaking. An interpreter needs to speak and be understood in at least two languages. Being fluent verbally in a second language takes special skills.
Simultaneous interpretation takes place when an interpreter interprets over someone talking.
If you went to a seminar and had an interpreter with you, the interpreter would verbally tell you what the speaker was saying, as the speaker was saying it. Consecutive interpretation takes place when a speaker talks then stops in order to have the interpreter interpret what was just said. An interpreter is a communication tool. An interpreter allows you to communicate immediately and effectively in a foreign language. The equipment required for interpretation could be as simple as a phone and as complex as complicated audio systems.