Small "s" sun. Not our Sun.

thats a star, our star is called sun

From https://www.merriam-webster.com/dictionary/sun:

    sun noun
    \ ˈsən  \
    1 a: often capitalized : the luminous celestial body around
         which the earth and other planets revolve [...]
      b: a celestial body like the sun : STAR

Or to quote Carl Sagan: "Across the sea of space, the stars are other suns."

that might need some correction...

Wikipedia states: The Sun is the star at the center of the Solar System.

According to some articles on the web, other stars can be suns as well, if they contain a planetary system.

In common language however "the sun" is typically our star. "a sun" might be other stars as well.

I think most people dont understand and think about the difference and thus think a star is a sun.

Commonly known as a star.

(But now I wonder: is there a difference between stars and suns?)

My understanding is that a star is a star regardless of what is or isn't in orbit.

A sun, however, needs to have planets to be a sun.

I searched if there are "free-floating" stars that don't have any planets in their field of gravity, and results essentially say "not since the early days of the galaxy". So nowadays all/most/the overwhelming majority of stars are suns. Very interesting!