Final answer:
In physics, a dislocation refers to a defect within a crystal lattice, including edge and screw types, and is characterized by the Burgers vector.
Step-by-step explanation:
A dislocation is a type of defect found within a crystal lattice. Particularly, there are two main types of dislocations: edge dislocation and screw dislocation. An edge dislocation occurs when an extra plane of atoms is inserted into part of the crystal lattice, causing a localized distortion. On the other hand, a screw dislocation is characterized by a gradual shift of a block of ions either downwards or upwards, forming a helical twist of the crystal structure. These dislocations are further characterized by their Burgers vector, which is a key concept in dislocation theory; if you were to trace a loop around the dislocation (known as a Burgers circuit), you would not end up at your starting atom due to the presence of the dislocation.