Hex Inverter Vs. Open Collector

Other Hardware General Electronics
1

I am just learning electronics and have difficulty differentiating between the hex inverter and open collector. Here is the specific question:

  1. Hex inverter, such as 74HC04: In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. Thus, when input is low, the output is high and the other way around.

  2. Open collector such as 74LS06 is basically a hex inverter with a pull-up resistor.

So, is it accurate to say that the main difference is that the open collector, instead of just being "LOW", actually "pulls" the output circuit to ground when low (basically, "connects" whatever is on the other side of the output to ground)? I know my semantics are terrible (I am new to this) but hope you understand my point. Is this a correct assumption? thanks.

2

Open collector or open drain gates only pull low, so a pull-up resistor is needed.

Standard gates have totem-pole (push-pull) outputs which either pull down if
low or up if high.

Tri-state outputs are push-pull outputs which can switch off both drivers so they
stop driving altogether.

Both open-collector and tri-state outputs can be connected together to form
a bus, open-collector busses are intrisically safe as no output can fight any other.

Tri-state busses need a protocol to only allow at most one output to be driving
at any one time.

Normal push-pull outputs should never be connected together (except when
paralleling gates for extra current driving).