What exactly are boundary points?

Are they just limit points? because i saw an example which said the bounday points of punctured unit open ball ie {(x,y)| x^2 + y^2 <1 , (x,y) not (0,0) } are the points described by x^2 + y^2 =1and the origin.

iThese are the limit points right?

Then what are the boundary points of Q --is it R?