Trees grow from the tips, gaining mass behind them. In bonsai the goal is to control how the tips grow (shape and balance) and manage how they gain the mass along the way. We use that growth in many ways; building mass to make branches bigger, to make entire parts of the tree bigger, or to put the finishing touches in the form of ramification.
The “clip and grow” term is used to describe letting a branch grow until it has 5 or more leaves, then trimming it back to one or two. This is performed during the growing season. Each node has a dormant bud where the leaf stem attaches to the branch, which can be signaled to grow when the branch is trimmed back. A dormant bud is circled in red below:
Over time dense ramified twigs can be built. Here is an example of a deconstructed Japanese Maple, which starts like this: