What is the difference between "accuracy" and "resolution"?

When looking at product specifications, you will see numbers for both "accuracy standard" and "resolution".

Accuracy standard is the acceptable margin for error that the gauge will read when compared to the true tire pressure. This number is often expressed as a percentage, for example ±2% Full Scale.

The "full scale" is always the maximum pressure that the gauge can read, for example if the maximum PSI a gauge can read is 100 PSI, and the accuracy standard is ±2% Full Scale, this means that ±2 PSI (or 2% of 100) is the margin for error for that gauge.

Resolution is the increment at which a gauge can read tire pressure at.

For example on a digital gauge, if the pressure readings show in increments of 0.50 PSI (1 PSI... 1.5 PSI ... 2 PSI ... 2.5 PSI) then this means the gauge has a resolution of 0.50 PSI.