There are two basic groups of tomato plants: determinate and indeterminate.  Determinate, also known as “bush types”, set all their fruit in a shorter period of time, do not need to be pruned and grow well in a cage. No staking is required.  Indeterminate tomato plants grow tall and are also referred to as “staking tomatoes”.  They continue to grow and produce fruit all season long and should be pruned.  Staking is required.