Sketcher entities can be constrained in two ways:
Dynamic Constraint Lines are displayed when creating geometric entities. Lines or points (called Dynamic Constraints) are highlighted to help you align entities relative to the Sketcher UCS or relative to other entities.
Manually added constraints are used to constrain entities to one another, or to apply conditions such as parallel or normal.
Fully defined sketches describe the desired relationships between parameters, making the finished sketch more stable and reliable. Future changes to the sketch will be easier and will not destabilize the rest of the sketch. The system has to make fewer calculations when working with a fully constrained sketch, so defining can help with performance.
