Here's a video of sheep being moved from one pasture to another. The shepherd is the one that takes care of and leads them. The Shepherd often has dogs that help round up the sheep and guide them to where they need to go. The bible shows us that Jesus is the shepherd of His people, watching over, protecting and guiding them.
Then said Jesus unto them again, Verily, verily, I say unto you, I am the door of the sheep.  All that ever came before me are thieves and robbers: but the sheep did not hear them.  I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture.  The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly.  I am the good shepherd: the good shepherd giveth his life for the sheep.  But he that is an hireling, and not the shepherd, whose own the sheep are not, seeth the wolf coming, and leaveth the sheep, and fleeth: and the wolf catcheth them, and scattereth the sheep.  The hireling fleeth, because he is an hireling, and careth not for the sheep.  I am the good shepherd, and know my sheep, and am known of mine.  As the Father knoweth me, even so know I the Father: and I lay down my life for the sheep.