Key(trials)

FFW= Front freewheel
Bash plate= A peice of metal underneath the frame to protect it when landing on things like rocks and walls, only really used on mods, hardly ever used on stocks.
Mod= A 20" trials bike-good for flicking around because of its weight.
24"= A 24" trials bike-only used for street not natural and comps.
Stock= A 26" trials bike-normally used for comps but also used for street.
Street= Riding things like kerbs and walls, you may see people in your local city doing this.
Natural= Natural is riding things like roots, rocks and big logs, competitions are held on this. A well known place for this is Hook Woods in Surrey
Trials competitions= Also known as comps, a rider makes their way round a course marked by small flags. The ain is to get as least dabs as possible.

If you have any more to add or change Just PM(personal message) me as my trials knowledge is not that great.

Thanks Jake.

Easy to understand. Just remember what they stand for if you get stuck just look at this page thanks