There are probably as many answers to this question as there are workshops and workshop presenters but,
In general, a workshop is a single, short (although short may mean anything from 45 minutes to two full days) educational program designed to teach or introduce to participants practical skills, techniques, or ideas which they can then use in their work or their daily lives.
Most workshops have several features in common:

• They're generally small, usually from 6 to 15 participants, allowing everyone some personal attention and the chance to be heard.
• They're often designed for people who are working together, or working in the same field.
• They're conducted by people who have real experience in the subject under discussion.