A great compound movement for the Triceps, Dips can be made more or less difficult with ease - dependent on your ability.
If you're new to dips, most gyms will have either a Dip Machine or an Assisted Chin and Dip Machine. A Dip Machine allows you to adopt the same dip position (but seated) and press down the selected weight of a stack (see 'More in this Section' for a demonstration). An Assisted Chin and Dip Machine has either a foot-plate or kneeler and a selectorised stack for you to offset weight against your bodyweight. Bench Dips is also a popular starting-point.
The more advanced at dipping can use a dip belt with weights and add variations such as Gymnastic Ring Dips (you can perform this exercise with TRX Bands too). Or, if you're really daring, Gymnastic Rings Dips with weight and Globe Gripz as demonstrated below...