Koha (software):

Koha is an open source Integrated Library System (ILS), used world-wide by public, school and special libraries. The name comes from a Māori term for a gift or donation.

Koha is web-based ILS, with a SQL database (MySQL preferred) backend with cataloguing data stored in MARC and accessible via Z39.50 or SRU. The user interface is very configurable and adaptable and has been translated into many languages,  Koha has most of the features that would be expected in an ILS, including:

Various Web 2.0 facilities like tagging, comment, social sharing and RSS feeds

Union catalog facility

Customizable search

Circulation and borrower management

Full acquisitions system including budgets and pricing information (including supplier and currency conversion)

Simple acquisitions system for the smaller library

Ability to cope with any number of branches, patrons, patron categories, item categories, items, currencies and other data

Serials system for magazines or newspapers

Reporting

Reading lists for members

Central Library’s KOHA is a Configured version of the System that suite the need of the Central Library and their Policy.

OPAC:

An online public access catalog (often abbreviated as OPAC or simply library catalog) is an online database of materials held by a library or group of libraries. Users search a library catalog principally to locate books and other material available at a library.