Can you connect an output from a logic gate to 2 or more logic gates or inputs?
In circuit complexity, the fan-out of a gate is the number of gates its output is connected to (similarly, the fan-in is the number of inputs to the gate). A circuit in which all gates have fan-out 1 is known as a formula. It is known that some $n$-bit functions can be computed by circuits of size $O(2^n/n)$ but require formulas of size $\Omega(2^n/\log n)$. It is conjectured that polynomial size circuits can compute more functions than polynomial size formulas, but this conjecture, known as the $\mathsf{NC^1} \stackrel?= \mathsf{P}$ question, remains unproved.