From AMS Glossary
The semipermanent subtropical high of the North Atlantic Ocean, so named especially when it is located in the western part of the ocean.
This same high, when displaced toward the eastern part of the Atlantic, is known as the Azores high. On mean charts of sea level pressure, this high is a principal center of action. Warm and humid conditions prevail over the eastern United States, particularly in summer, when the Bermuda high is well developed and extends westward.