Still Sealed (SS) As good as it gets. Unopened and most likely perfect all around.
Mint (M) Absolutely perfect in every way. Usually only sealed LPs. Near Mint (NM or M-) A nearly perfect record. The record shows no obvious signs of wear. Covers show no more than the most minor defects. The same holds true for inserts, such as posters, lyric sleeves, etc.
Near Mint Minus or Very Good Plus Plus (NM- or VG++) Just a hair more wear than NM, but still very close to Near Mint overall. Vinyl may have nominal sleeve or paper scuffs, cover may have hint of wear. VG++ will be just a fraction below NM- due to one additional tiny defect.
Very Good Plus (VG+) Album and cover show some light signs that it was played and otherwise handled with care of it. Record surfaces may have slight surface scuffs or very light scratches that don't affect play.
Very Good (VG) Increased scuffs or light scratches, surface noise evident upon playing. Covers and labels may be marred by writing, or have tape or stickers, or minor seam splits.
Good Plus(G+) Certain background noise, possible click or pop, flawed item. Covers heavily damaged, major splits, tears, writing, etc.