Bunch of people gathering and trying to win some money.
Live games offer more tells and acting, it is up to you decide to the best of your ability to narrow down what your opponent has and act accordingly as if you were playing online. Very important how you portray yourself too because other people try to pick up on tells you show to determine their next decision.
Personally at live games I tend to feel a minor anxiety initially but I mellow out as the game goes on and I get familiar with my opponents. You also might feel a bit of an overwhelming rush inside your body when getting good hands or attempting to bluff.
Live games are a great way to play and I strongly reccommend it.
P.S. You'll find more fish / recreational players who are often intoxicated and make bad decisions.