A more thorough explanation:

A notary seal is a device used by a notary public to make an imprint on a notarized document. It can be either an embossed seal or a rubber-stamp seal.

An embossed seal is a notary seal that is impressed onto a document, raising the impression above the surface. This type of seal is required in some states and on some documents notarized for federal purposes. It clearly identifies the original document because the seal is only faintly reproducible. For example, if a document has an embossed seal, it means that the notary public physically pressed the seal onto the paper, leaving a raised impression that cannot be easily copied.

A rubber-stamp seal is a notary public's official seal that is ink-stamped onto documents and is therefore photographically reproducible. It typically includes the notary's name, the state seal, the words “Notary Public,” the name of the county where the notary's bond is filed, and the expiration date of the notary's commission. For example, if a document has a rubber-stamp seal, it means that the notary public used a stamp to imprint the seal onto the paper, leaving an inked impression that can be easily copied.