What is done in a workshop? How does it differ from an academic conference? I have done some research on this, but I still don't know what is carried out in a workshop. What activities are arranged? How are they different from conferences?
The reason why it is difficult to tell what workshops are about is because it is a catch-all category that many different types of academic meeting are labelled as. To illustrate, let me give examples of the nature of some of the events that I have attended in the last two years that all use the same word "workshop" to describe themselves:


A "baby conference" attached to a full-size conference, where the small meeting simply isn't large enough to meet on its own yet.
A project meeting for researchers who are all funded by the same large grant
A planning and discussion session aimed at helping determine the direction of a field
A joint industry/academia fact-finding meeting sponsored by an industry consortium
A specialty conference attended by around 100 people
A premier conference attended by several hundred people
A working meeting by a standards development group


The length of these meetings ranged from a single afternoon to a full week. Their programs ranged from nothing but loosely structured discussion to a full-on tightly packed conference schedule.  The level of peer review ranged from non-applicable to minimal to full-on single-blind review and revision.

In short: a workshop is whatever it wants to be, and different ones serve different purposes in the academic ecosystem.