Describe what do you mean by the term SEO and SEM with respect to internet and computer technology

Search Engine Optimization (SEO)
Search engine optimization is also known as SEO. This is the process of improving the amount of traffic and the quality of traffic to a website from search engines using algorithmic search results for keywords.

Search Engine Marketing (SEM)
An advertising strategy designed to bring visitors to a particular web site. Typically used in conjunction with search engine technology to deliver ads for businesses to appear in search results with other related content.

What is a Screencast? How it is relevant to online content developers and bloggers. What is the difference between screencast and podcasting?

Screencast
A screencast is digital recording of a computer screen, usually with audio narration. They can be used to show users how software works and can help report problems in software. The screencast software is typically used by video publishers of youtube.

Podcasting
Podcasting is a kind of audio broadcasting that uses the Internet, like an on-line radio show. The name was created by combining “iPod” and “broadcasting”. Podcasting involves making one or more files available in an RSS feed. A pod-caster (the creator of the podcast) makes a list of music and/or other audio files and makes the list available for other users to retrieve.