What are the realms of Hades and Elysium?

Hades and Elysium are both realms of the afterlife. Hades as a realm takes after the god Hades. Hades, the brother of Hera, Demeter, Hestia, Poseidon and Zeus, was the eldest son of Cronus, the Titan. According to Greek mythology, Zeus managed to free his siblings and together they successfully waged war against the Titans. After emerging victorious, Zeus, Poseidon, and Hades drew lots to apportion the realms. Zeus received control of the sky, Poseidon received control of the seas, and Hades received control of the underworld. The land on earth was left available to all the gods and goddesses.
The underworld (Hades) is considered an unseen realm where the dead go after their lives on earth are extinguished. Hades is also considered home to all other beings living below the earth. The underworld has been portrayed to exist at the outer edges of the sea or deep below the surface of the earth. Hades is accessed through several rivers that are visible in the living world, and they include; River Styx, Acheron, Phlegethon, Lethe, Oceanus, and Cocytus.
Hades is made up of compartments where different souls exist, and they include the following:
Mourning Fields: This section of the underworld is reserved for souls that wasted their lives chasing after unrequited affection.
Asphodel Meadows: This section of the underworld is reserved for those who lived an average life and committed no serious crimes.
Tartarus: This section is also referred to as “Home of the Titans.” It is reserved for those who committed serious crimes and are serving their punishment. Tartarus is where Zeus cast the Titans after they were defeated. According to some accounts, it is not considered part of the underworld but a different realm beyond it. However, Hades provides the only access to it.
Elysium: This section of the underworld and afterlife is reserved for distinguished souls that include individuals related to the gods, heroes, and the righteous. The souls existing in Elysium are free from any torment, anguish or pain. However, just like Tartarus, Elysium is not considered a part of Hades by some accounts. These accounts are supported by the assertion that Zeus’s son Rhadamanthus is the ruler of Elysium.
http://users.scc.spokane.edu/JRoth/Courses/World%20Masterpieces%20271/Links/TEXT_SPECIFIC/Classical%20Greece%20Underworld.htm

http://www.classics.upenn.edu/myth/php/tools/dictionary.php?method=did®exp=1018&setcard=1&media=1&link=0

https://www.theoi.com/Kosmos/Elysion.html