First their differences. Then please tell me if you think patents are justified or not. After all, there was no theft involved and the original creator has not been denied his creation since it has been independently created by another using his own resources. No one can claim ownership over a products value in a free market. They just have to accept market wisdom. So why allow them to patent it and thereby create an artificial monopoly? Why not just let the market decide the winner? It should serve to reduce prices for consumers significantly too. Do you agree? Why/ Why not?
Copyright is a type of protection for the expressions of an idea (not the idea itself): pictures, paintings, screenplays, songs, and so on.
Patents are for inventions, novel ways of doing something. There are also patents for scientific discoveries.
Trademarks are words or symbols used commercially. The protection isn't for the symbol, it's for the way the symbol is used to refer to the brand or company.
I disagree with genetic patents; something found in nature should not be the intellectual property of any single person or entity. However, I think patenting inventions under the original concept of a patent is a good idea (or it would be impossible for small business to develop a product and succeed, because big businesses would just steal their ideas and swamp them with their vast marketing budgets). That said, there are definitely corporate patents (Apple has apparently patented square symbols with rounded corners) that border on the absurd, and the spirit of innovation patents were developed to protect is being lost.
Hope this helps!