This document defines and discusses different types of e-resources, which are electronic resources that require computer access to deliver data collections. It identifies two major types of e-resources: online resources like e-journals, e-books, databases and websites, as well as other electronic resources like CD-ROMs and diskettes. The document also outlines key advantages such as multi-access, speed, content, mobility and convenience, as well as disadvantages including requiring special devices, screen glare, and lack of familiarity compared to print books.