Rim, edge... Aren't these just different words for the same part of a coin? No, not at all... The rim and edge are as different from each other as the obverse (or ) and reverse (often called the ). When it comes to coins, many people may confuse the rim and edge because these terms often have similar definitions when used in other contexts. For example, you might say you're going to which means the edge of the cup.

But rims versus edges on coins? Well, in numismatics, the rim and edge simply aren't one and the same...

Rim
The rim of a coin refers to the raised ridge encircling the circumference of the obverse and reverse of a coin. The rim is fully visible when looking squarely at the coin's obverse and reverse. On most modern coins, the rim is unadorned, taking on the appearance of a thick, solid border or frame around the obverse or reverse. On many classic coins, the rim may be ornamented with denticles or other aesthetic frills.

Edge
A coin's edge is also known as the third side of a coin, and it's often one of the least photographed or illustrated portions of any coin. The edge may be plain (flat), reeded (has lines or grooves), include edge lettering, or boast other features to bolster the coin's security or offer other visual or technical benefits. The edge is every bit as important to study as the rest of a coin and can even be used to determine whether a coin is authentic, i.e. - many cast counterfeits exhibit a telltale seam around the edge.

To read the complete article, see:
The Rim Versus Edge of a Coin(https://www.pcgs.com/news/rim-versus-edge-of-a-coin)