Web Hosting Glossary: U

Unix: Unix is a computer operating system designed in the early 1970s by Bell Labs. Unix and Unix-like platforms such as Linux are the most popular platforms used on web servers, because of it's stability and cost-effectiveness.
Upload: The act of transfering files or data to a web server from your local machine.
Uptime Guarantee: Uptime guarantee is a percentage of time that the host can guarantee that a client's web site will stay up and running without any problems.