In the United Kingdom the name of a fruit or fruits followed by juice can only legally be used to describe something which is 100% fruit juice.[1] This is because of the Fruit Juices and Fruit Nectars (England) Regulations and the Fruit Juices & Fruit Nectars (Scotland) Regulations 2003.[1][2]
Juice can be bought from a store, already in bottles. Companies sell fruit juice just like any other drink. Juices are made by squeezing the juice out of the fruit.
If something has a lot of juice in it, it is said to be juicy. Juice does not have to be a drink. It can just be a liquid contained in something.