The guitar solo was common throughout all rock music from Chuck Berry
onwards, but wasn't so much a demonstration of technical ability until the 80's the era of heavy metal
. The key element in 80's soloing was virtuosity
; i.e., playing very fast. This is why guitar solos are often associated with shredding
Guitarists such as Eddie Van Halen, Ritchie Blackmore, Steve Vai, Joe Satriani, Yngwie Malmsteen, Randy Rhoads, John Petrucci and countless others are known for their serious chops. They are famous for "breakneck pace" guitar solos.
Of course, the 80's guitar solo is by no means the only type of guitar solo, it just deserves special mention. Guitar soloing, as I said, has been going on for as long as rock has existed. Famous non-shredder guitarists include Jimi Hendrix, Jimmy Page (of Led Zeppelin), Dave Gilmour (of Pink Floyd), and many more.