In the 500 hPa weather chart, what do the lines 520, 528, 584, 588 and so on specifically represent?

Look at the picture to speak

The standard air pressure is 101325 Pa = 1013.25 hectopascal? Below it is low pressure, and above it is high pressure

500 hectopascal weather map Medium? Look at my icon. The low pressure center

520? 528? 584? 588 all represent the same air pressure on this equal line? They are also about the same height

Fluctuate in a sinusoidal manner. For curves, the crests are called ridges and the troughs are called troughs.

The trough is a system that brings clouds and rain, while the ridge corresponds to sunny weather? Line A is a high-pressure ridge? Line C is a low-pressure trough? Area B is sunny? Area C is rain and snow