The Baltic States refer to a region of three historically similar, but unique countries : Lithuania, Latvia, Estonia.
Baltic States have been occupied by Soviets in 1940 – 1941 and 1944 – 1991. In 1990 – 1991 Lithuania, Latvia and Estonia redeclared independence, in 2004 joined NATO and Europe Union.
Lithuania and Latvia has rather similar culture, landscape, traditions. Estonia has a culture which ties with Scandinavian countries.
All three Baltic States are sea countries.
Article in Britannica: https://www.britannica.com/place/Baltic-states