SaaS
SaaS refers to software that is delivered over the Internet as a service on demand. SaaS differs from the traditional method of purchasing software on CD-ROM or downloadable file to be installed locally on the user’s computer. SaaS vendors develop and operate software applications for customers to use, but the software is usually run all or in part on the vendor’s hardware - a cloud hosted environment. It is a new software distribution model, one that is inevitably the way all software will be delivered in the future.

SSD
A solid-state device or drive (SSD) is the next generation of data storage. The architecture of an SSD does not employ rotating disks at all. An SSD utilizes a memory chip with erasable, writable cells that can hold data even when powered off. Solid-state memory is in popular consumer devices such as iPhone, digital cameras, etc.

SSO
It stands for Single Sign-On authentication. With SSO, user just needs to login once (e.g. to your website or some other web-based application) and he immediately gets authenticated to PHPKB powered knowledge base automatically.