How did militaries of Sparta and Athens different

The main difference between them was that Athens focused on the sea while Sparta focused on the land. Spartan boys went into training when they were only 7 years old. Every man had only one occupation and that was the soldier. They were a fierce and unmatched fighting force in Greece at the time but only on land. On sea Athens dominated with its superior navy with a ship design called the Trireme. It was a lot more powerful in battel than previous ships at the time.