Open Question: QUESTIONS ABOUT W9 FORMS. PLEASE HELP!?

OKAY SO I KNOW THAT A W9 FORM IS FOR SELF BUISNESS CONTRACTORS. BUT WHAT IM WONDERING IS,,, WHEN YOU FILL A W9 FORM OUT DOES THAT LET THE IRS KNOW THAT YOU ARE WORKING? AND DO I STILL GET A W2 FORM AT THE END OF THE YEAR IF IM DOING THIS?? IM SO CONFUSE.