If an idea stays in your head, it is just an idea.
If you convert an idea into a song, a product, a design or a book then it becomes intellectual property.
Now the idea has value and may need protecting. Protection can come in the form of a patent, copyright or trade mark. This protection is an incentive to firms to go on and produce the product.
Patents protect the working parts of a product, what they do, how they do it, what they are made of and how they are made. A patent gives inventors control over their invention for twenty years.
This can stop other would be manufacturers from making a similar product using their ideas. A patent gives firms a competitive advantage, they can establish their product in the market without any competition and charge higher prices which helps to recover their research costs. They could also sell the rights to the invention, or licence the invention to another manufacturer.

Copyright laws protect the image of the product. The reason a business would want to protect images of their product is to ensure they are only used in situations that benefit the product and brand.
Finally the name and company logo are protected by trademark. This is done by registering the product name or symbol with the intellectual property office. Business names and logos are valuable trademarks because they are a sign which distinguishes a firms products from its competitors.