There are two main Groupings of exercises you could be doing in the gym in terms of strength or Hypertrophy: compound and isolation lifts.

Compounds lifts are categorized by their use of multiple muscles in conjunction: ie. Deadlifts, Squats, Benchpress; while some examples of isolation exercises (to use one muscle at a time) would be: bicep curls, chest flyes, tricep Pushdowns; intended to put the load of the weight on one muscle. Now, each of these movements have a place in any program.

Compounds are great for developing overall functional strength: they workout several muscles at a time and allow for higher workloads via. direct weight; while isolation exercises help develop the strength of one direct muscle, which also feeds into the ability to lift more in your compounds: these two exercises groups are complimentary and actually help you get better within the other and build more muscle through this process [as strength is often our best indicator of an increase in muscle or muscle-recruitment].

Both compounds and isolation movements have a place in your program, and not only do they have a place: but they likely, SHOULD be in your program.

Thank you for your time, I appreciate you taking the time to read this; have a Great rest of your day/night.