When a break statement is reached the flow of control jumps outside of the current loop.

var
   loop:longint;

begin
   for loop:=1 to 100 do begin
      if loop=50 then break;
      writeln(loop);
   end;
end;

Will output 1 to 49, as the loop it broken when loop equals 50.

Source: Reserved Words

See Also:

continue, exit, for, repeat, while.