Co-op and internship programs

• As an international student, can I take part in co-op and internship programs?
• There’s a specific employment location on my co-op or post-graduation work permit. Can I work somewhere else?
• There’s a specific occupation on my co-op or post-graduation work permit. Can I work in a different field?
• My co-op work permit says “not authorized to work for any employer other than stated”. What does it mean?