A comparison compares two voltages, can comes out with a digital high or low depending on which input is higher.
A Schmitt Trigger fires high on one low voltage and low on another voltage. A 555 Schmitt Trigger goes low on the 2/3 power supply level, and goes high on the 1/3 power supply level.
You can make a Schmitt Trigger with a comparator and 2 resistors.
A Schmitt Trigger fires high on one low voltage and low on another voltage. A 555 Schmitt Trigger goes low on the 2/3 power supply level, and goes high on the 1/3 power supply level.
You can make a Schmitt Trigger with a comparator and 2 resistors.