1) Burger vector is measuring quantity for measuring the intensity of dislocations.
2) The magnitude of burger vector gives the intensity of dislocation and direction of it gives the direction of dislocation.
3) When we draw a loop circuit around the dislocated region, if there is dislocation then the loop will remain incomplete and to join the loop and make it complete we use burger vector.
4) For example for Edge dislocation, if we try to draw a loop around the dislocation, due to dislocation we will get an incomplete loop, so we join the end to start of loop by burger vector.
5) Taking the same procedure for Screw dislocation, when we connect the loop in screw dislocation, we get an incomplete loop where the layer is dislocated and there we join the loop by burger vector.
6) The burger vector for edge dislocation is according to view of plane while in screw dislocation it is parallel to dislocated plane.
7) When we start looping, moving horizontal by x units then moving vertical by y units. But if we have a dislocation the loop will stop at dislocation, leaving some space it will again continue to loop to same start point, the left space is filled by burger vector.
8) Same procedure is for Screw dislocation, when we move by x unit horizontal y unit vertical, and again horizontal by x unit, while crossing dislocation we will get an extra distance perpendicular to plane of dislocation and then again continue to initial point, the extra space is filled by dislocation.