There were important similarities and differences between these two poleis.
The major similarity is that they were both Greek city-states that were strong and to some degree imperialistic. This means that they had religious beliefs and language in common. It also meant that they had basic ideas like the rule of law and the acceptance of slavery in common.
Beyond this, the two poleis were very different. Sparta was a much more war-like society. It kept helots to do the work and let its men and women dedicate themselves to making a stronger military society. Athens put much more emphasis on intellectual and cultural things. Athens had more democracy than Sparta did, but Spartan women had more freedom and rights.
In these ways, these two were similar in very basic ways, but had many important differences as well.