(1) One of the few places you can walk barefoot, revealing your toe webs, and be admired for having them.
(2) A damp geographical interlude between wet and dry.
(3) A place where sea weasels come ashore to pillage and molt.
(4) The only solid land that bathes regularly.
(5) Buffer area between water and earth. Some of this and some of the other.
Beach is a strip of land, sloping toward water, that may be sandy, or muddy, or rocky, or gravelly but generally not too solid.
It is wet a lot, being the strip of land lying between low and high tides.
Around lakes a beach is usually sandy and flat.
If warm and clean enough, any ocean beach may attract nudists, who are a favored prey of the larger and more aggressive sea weasels.