Electric guitar playing questions?

by Brent
(Australia)

Went to see a local cover band with a guitar playing friend. I'm not a musician and was impressed with the lead guitarist. My friend said he was all show and just 'running lines' and 'hijacked' some classic rock songs. When when my friend said the lead guitarist "hijacked" several classic rock songs, I got the impression he was talking about the extended jams went so far left field they didn't sound like the original songs anymore, and it took quite a while for the band to come back together. What do theses two expressions mean in rock music ie. “running lines” and “hijacking”? And if "hijacking" has a different meaning, is there a term which describes the above where a lead guitarist took song/songs go right away from the original version in a guitar solo, extended jam?