All coins have two sides, an obverse and a reverse. The obverse is the front or the "heads" side, the reverse is the back or the "tails" side.

Those symbols are the obverse and reverse of the Great Seal of the United States. The eagle is the obverse and the pyramid is the reverse.

"Obverse" refers to the front of the coin (usually the side with the portrait), as versus the "reverse", or back, of the coin.

The reverse of any coin is its back. The portrait is on the obverse, or front.

The term "reverse" refers to the back side of a coin, as opposed to the "obverse", or front side. On US coins, the obverse side is the one with the portrait and (except for the presidential dollars) the date. On foreign coins, it is not always easy to determine which side is the obverse and which is the reverse, although a good rule of thumb is that the side with the portrait, crest, or name of the country is probably the obverse.