Slogan. Motto. Promise. The music of expression ... A striking image, a name with a certain ring to it. They make your business distinctive, they characterise it and they advertise your company all by themselves. They can protect your image with a word, a picture, a combination of these two forms or a three-dimensional shape.
When you register a trademark, you as its proprietor, acquire an exclusive right to use it for the protected goods and services and can prohibit others from using it. A mark is initially registered for ten years but this can be extended by ten years at a time as often as you like. Marks can last till the cows come home. They can go on forever.