Earth normal was a comparative term sometimes used to describe a planet's vital statistics in relation to those of Earth. Earth sea level referred specifically to the gravity at sea level.
Enterprise NX-01 kept its gravity at Earth sea level, unlike some Earth Cargo Service freighters, including the ECS Horizon and ECS Fortunate. (ENT: "Broken Bow", "Fortunate Son") In 2151, after witnessing Captain Keene's spectacular catch, Matthew Ryan said he'd like to see Keene make the same catch with the gravity plating set at Earth sea level. (ENT: "Fortunate Son")
An insectoid starship, utilized by an ancient insectoid species of unknown origin, found orbiting Questar M-17 by the USS Enterprise in 2269 was determined to have air and artificial gravity within two points of Earth normal. (TAS: "Beyond the Farthest Star")
Lactra VII was described by Spock as having gravity and an atmosphere that was Earth normal. (TAS: "The Eye of the Beholder")