A Near Mint card looks like it has never been played without sleeves. Small allowances can be made, but the card generally shows no wear.
The border of NM card can have small white spots, but they must be very few and very small. When the card is inspected under bright daylight, the surface must generally appear clean. It can have a few minor spots, but scratches are never allowed for NM cards.
For Excellent cards it is almost always clearly visible upon first inspection that the card is not in perfect condition. However, although the damage is clearly visible it is only of minor severity.
Excellent cards usually have a couple of white spots at the corners or around the border. The surface may have minor scratches, that are visible upon closer inspection.
Cards in Good condition usually show strong wear all around the card. The edges and corners have many white spots, the surface usually has scratches and the card usually has accumulated some dirt on its surface. However, the card still only has damage that stems from regular play. The card has no water damage or bends whatsoever.
LIGHTLY PLAYED (LP)
Lightly Played cards may have border or corner wear or even just slight scuffs or scratches. There are no major defects such as folds, bends or issues with the structural integrity of the card.
Played cards are in acceptable conditions. Condition can have border wear, corner wear, scratching or scuffing, creases or whitening or any combination of mild examples of these marks.
Cards in Poor conditions are literally destroyed. Do you remember when Mum used to wash your jeans with your cards inside the pockets? That's the same!