Your a lone wolf, always moving and never staying in one place very long. Now you have crossed into a dangerous pack territory. Your called out in a instance. "Hey, what are you doing on our land?!" You turn to face them, and meet a black she-wolf. She is graceful, but clearly dangerous. You regard her carefully. "Now, are you bing to join the Frightstorm Pack, or run?" You look at her, making your decision. You nod to her, causing her to a smile "Then let's get moving."
This is the head of the pack, any problems you have are to be brought to the attention of the alpha, and/or their mate. They assign who the beta and delta will be if the previous ones can not produce an heir and deal with other packs if they attack. If there is no heir, the alpha will decide who is worthy of being the next alpha.
This is the second in command. They help the alpha with other pack and becomes Alpha is the original alpha doesn't have an heir and has died before choosing a successor. When the alpha goes to other pack, the beta gets the power and watches over the pack. The beta usually helps with the hunters of the pack.