good & bad bishops?

i know ive seen this explained before but I either did not read it or I was too weak at the  time to get it where can I get an idea of it.  I thought it was just if it had a clear line.  thanks

bad bishop is a bishop hemmed in by the player's own pawns :

After just a few seconds looking at that position, I don't see anything that back can attack. The base of white's pawn chain is defened by the king on the opposite color square of the bishop. Can't take on b4 for obvious reasons. g2 and h3 just sit as is and get away clean. How does black attack?

okay xbig boy imagineit in the opening it was like that who would win

 I don't get it.

okay xbig boy rebs postion might be drawn but in any other position with other pieces bad bish vs good bish the good bish will win 90 out of a 100 for  and woth a good bish its easier to ge a attack going

Reb explained the concept... the takeaway is you've got to analyze the positions, sometimes the bad bishop isn't so bad, sometimes it is. Reb's position is interesting. I'm not so sure it's as drawn as it looks, I think black has some chances pushing his king side pawns, the white bishop need has a hard time defending and protecting b4 pawn.  FWIW i don't quite understand Mr30 either.

damn everyone used to understand me in my old acount krish30 whats wrong

you have to look at how many squares the bishops control and can move

black had much more mobility and controls more squares while white is trapped behind his own pawns

thankyou everyone for the helpi finally found out how to view my post!  thanks to all for makeng this topic interesting!

Yep, there is a difference between good/bad and active/inactive bishop. White can have a bad bishop because his pawn chain is on the same color, but if he puts that bishop on a long and open diagonal, his bishop becomes active. Black can have a good bishop, because his pawn chain doesn't restrict the piece, but it is placed on a side of the board and can't move to much squares because of white's pawn chain. So white may have a "bad" bishop, but it covers more squares and it is thus more dangerous. This applies if the two bishops aren't the only attacking pieces left.

I'm sure somebody could explain this much more clearly than me.

Before this help I thought the good and bad bish were the colored squares that each covered now i understand that it is more the position with the  availible squares that gives the designation does this mean that there can be 2 good bish per side?