More than one item which share some property, even if it is only the interest of the person that identifies the items as being members of a collection. The quality of a collection is sometimes judged by other properties, such as completeness, organization, or intrinsic value of its member items. At root, Everything may be a collection of its users expressions.

In a library the collection is an organisational unit and the full compliment of information sources are called the libraries' collections.

Each library collection has a collections policy stating what is in the collection, why it's in the collection and how the collection is aiming to serve.

Typically library collections include:

  • In public/town libraries:
  • In university libraries
    • A teaching collection of materials to support the undergraduate teaching at the university. This typically includes desk copy and similar services, since these materials have surges of interest and must be rationed.
    • A research collection, with all the key books, journals and documents in all the areas of active research being conducted at the university.
    • Special collections. Special collections typically start a private collections of researchers who collection comprehensive collections in their own narrow field and then donate the collection to the university on condition that it is maintained. Once part of the university library the special collection becomes a highlight to be cultivated and promoted, since well-known and well-studied special collections can bring new researchers and research funding to the university. Most universities have a special collection related to local history or regional history.
    • A light reading collection. Many university libraries have a donation-only light reading collection for the enjoyment of the university students and staff. Novels are donated to the collection but no new books are bought for it from central funding.

In many programming languages, a data structure used to contain zero, one, or more objects. In the Java programming language, for example, collections are provided through the Collections Framework API in the java.util package; in C++, they are provided by the Standard Template Library.

The choice of a suitable collection data structure should be done with regard to the use of that collection, and usually the choice can make a noticeable difference in application performance. To this end, collection frameworks typically provide a variety of data structures; a set for example is a container that does not support duplicates, nor imposes a particular sort order. A multiset or "bag" allows duplication, while algorithms that require searching are often most efficient using sorted structures. The linked list allows rapid insertion and deletion of elements, while a flatter structure such as an array allows random access in constant time, but is typically more expensive for insertion and deletion. More advanced collections include the map, hash table, or tree, in which the data structure not only includes the objects, but also represents some relationship between them.

Both the STL and the Java Collections Framework also embody common algorithms, such as sorting and searching, that can be applied to collections in an abstract fachion without knowledge of the underlying implementation. There is commonly a requirement for conversion to and from legacy data structures such as arrays. The simplest algorithm is the notion of an iterator, which provides a mechanism to return the elements of the collection, one by one, for use in a loop.

Col*lec"tion (?), n. [L. collectio: cf. F. collection.]

1.

The act or process of collecting or of gathering; as, the collection of specimens.

2.

That which is collected; as: (a) A gathering or assemblage of objects or of persons.

"A collection of letters."

Macaulay.

(b)

A gathering of money for charitable or other purposes, as by passing a contribution box for freewill offerings.

"The collection for the saints."

1 Cor. xvi. 1

(c) (Usually in pl.)

That which is obtained in payment of demands. (d) An accumulation of any substance. "Collections of moisture." Whewell.

"A purulent collection."

Dunglison.

3.

The act of inferring or concluding from premises or observed facts; also, that which is inferred.

[Obs.]

We may safely say thus, that wrong collections have been hitherto made out of those words by modern divines. Milton.

4.

The jurisdiction of a collector of excise.

[Eng.]

Syn. -- Gathering; assembly; assemblage; group; crowd; congregation; mass; heap; compilation.

 

© Webster 1913.

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