1) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

2) Elvis Presley, often referred to as the "King of Rock and Roll," has sold over one billion records worldwide.

3) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.

4) Kim Kardashian West is an American media personality, businesswoman, and socialite. She gained fame through reality television show "Keeping Up with the Kardashians" and has built a successful brand empire encompassing fashion, beauty, and other ventures.