ms_attack
Visionary
Platinum Level
Basically, in terms of pure play, there is no difference between a player being weak or strong when playing online. However, some players have tells in live poker that you can't see online. For example, a player may be extremely nervous when he bluffs or scratches his neck or somewhere else on his body. Also, many players talk more live than online and so you can experience some tells. Professionals often try to engage their opponents in conversation and can gather information that they can use to their advantage. Pius Heinz, for example, attended a few courses on tells and psychology before winning the wsop in order to use this information to his advantage and ultimately win the WSOP. It can be the smallest micro moves that tell you something about your opponent at the live table. You don't see and hear things like that online.