workshop,forum 和seminar的意思与区别?

in common usage (USA) seminar is very similar to lectures,that there is one lecturer providing info and the audience is more passive.They just listen.
A forum is like a discussion panel,there may be a group of main speakers sitting around a table discussing issues mutually.Open discussions with the audience is very common too.
Workshop,sometimes is a overly-hyped word.But it could mean a seminar,with the typical lecturer and audience.In addition,there will be planned exercises and activities that the audience could do during the workshop to get them more involved.

seminar
n.
1. (大学)研究班, 研究班讨论会[课程]; [美]专家讨论会
2. 讲习会; 任何讨论会
n.[C]
1. (大学里由教授指导的)研究班,研讨
workshop
n.
1. 工场, 车间, 工厂
2. 专题学术讨论会
3. 讨论会会议录
4. 专题研究小组, 学部...