Broadly intellectual property, or IP as it is commonly known, is what you use to protect your products and services. You can't protect an idea or concept but you may be able to protect the product or design which is developed from the original idea.
IP is also a business asset. If you are running a business your business will probably have IP and it is just as valuable as other assets which your business may have such as premises, staff etc. In fact it's not unusual for IP to be of more value than these other more tangible assets.
There are four main types of IP:
Patents protect the functional aspects of a product or process - ie how something works. They can't protect such things as names and artistic works.
Trade marks are "signs" which distinguish your goods or services from those of your competitors. They are often words, logos, slogans or a combination of these. They form the basis of your brand.
Registered designs protect the visual appearance of a product. This can include such aspects as the shape, colour and ornamentation of the product. They do not protect how a product might work.
Copyright protects "creative works" - ie literary, artistic, dramatic or musical works. However this is taken in a very broad sense and includes such things as website content. Copyright does not protect inventions.
For more specific information on each type of IP click on the links on the right.