Are Beams and Trails similar or do they do the same thing?
long story short....
A Beam Is an object connects two Attachments with a beam of light or texture. A Trail is an object is used to create a trail like effect between two points
Here are some links to some websites you may find interesting.
http://robloxdev.com/learn-roblox/all-tutorials
http://robloxdev.com/