I would like to know the difference between collection and Collection. I know Collection is an interface provided in the java.util park but I don't have any idea about 'collection'.
Without knowing the context its a little hard to say, but I suspect "collection" is probably being used to define a data structure used to store objects without the writer wanting to make a specific reference to the Collection interface (which defines a particular type of collection). So an array could be considered a collection, but not a Collection. Understand?
Actually in Java there isn't anything called "collection" with a lower case c.
you will find Collection which you already mentioned, but also Collections, which is a class of static methods to do things like sort, and binarySearch on a List.