Sylow's Theorems are fundamental results in group theory, a branch of abstract algebra. They provide information about the existence and number of p-subgroups in a finite group, where a p-subgroup is a subgroup whose order is a power of a prime number p. The theorems help in understanding the structure of groups by focusing on their subgroups related to prime factors of the group's order. The first theorem states that for any prime p dividing the order of a group, there exists at least one p-subgroup. The second theorem gives conditions on the number of such p-subgroups, while the third theorem states that all p-subgroups are conjugate to each other, meaning they are structurally similar within the group.