periods vs semicolons

[Nessie]

Hi,
It seems to me that full stops (periods) and semi-colons have the same grammar punction - they both can be used at the end of a sentence and to begin a new sentence. The trouble is, I don't know when to use which.

Please shed some light on this.
Many thanks,
Nessie.
_________________
:(... something we never have again, I know... I guess I really really know.. :(

Sorry seems to be the hardest word...

[Yankee]

.
Have a look here, Nessie:
http://grammar.ccc.commnet.edu/grammar/marks/semicolon.htm
.
_________________
"Nearly all men can stand adversity, but if you want to test a man's character, give him power." ~ Abraham Lincoln