POP3 - is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection.
Shareware - trial based or limited copyrighted commercial software that is distributed without payment.
Wiki - a collection of Web pages designed to enable anyone with access to contribute or modify content.
Social Networking - can be defined as a community of people/users with similar interests/activities or interested in exploring those of others.
Cloud Computing - is where dynamically scalable and often virtualized resources are provided as a service over the Internet.
Source: Wikipedia.org, Dictionary