What is the difference between Site Definition and Site template?

Answer:

1. To create or use site definition you need server admin access, but site template can install from web UI by site owners.
2. Site definition supports feature stapling, but for site template additional features must be activated in gallery.
3. Site definitions are stored in hard disk, but site templates are stored in content DB.
4. Site definition can provision multiple webs, but site templates for single web only.
5. Creating site definition is relatively complex then site template creation.