The Wolfram Language supports an extremely wide range of mathematical notation, although often it does not assign a predefined meaning to it. Thus, for example, you can enter an expression such as x⊕y, but the Wolfram Language will not initially make any assumption about what you mean by .
There are some forms which look like characters on a standard keyboard, but which are interpreted in a different way by the Wolfram Language. Thus, for example, ∖[Backslash] or Esc displays as ∖ but is not interpreted in the same way as a ∖ typed directly on the keyboard.
Most operators work like and go in between their operands. But some operators can go in other places. Thus, for example, Esc and Esc or ∖[LeftAngleBracket] and ∖[RightAngleBracket] are effectively operators which go around their operand.