Final answer:
A group of things put together because they are alike in some way is best described as a collection, which refers to items or entities that share common characteristics and are brought together for a specific purpose.
Step-by-step explanation:
A group of things put together because they are alike in some way can be referred to by several terms. However, in the context of the options given, the most appropriate term is collection. A collection is an aggregation of items or entities that share common characteristics and are brought together for a particular reason, such as a stamp collection where all items are stamps.
Other terms like gathering, assemblage, and aggregation can also denote a group of similar items but are often used in different contexts. A gathering is more commonly used for groups of people, while an assemblage can refer to both items and individuals brought together for a specific purpose. An aggregation is a general term for a collection of things but lacks the connotation of deliberate collection that is implied in 'collection'.