Obverse

The obverse is the front of a coin, the side commonly called heads, and it normally carries the principal portrait or figure along with the date. The opposite side is the reverse.

On US coins the obverse usually also carries LIBERTY and the motto IN GOD WE TRUST. The Morgan silver dollar shows a left-facing Liberty head on the obverse with the date below. The American Gold Eagle uses an adaptation of the Saint-Gaudens Liberty design, a standing figure with the date at the lower right. Pre-1933 US gold covers several obverse designs across the $2.50, $5, $10, and $20 denominations, and the obverse is generally what identifies which type a coin belongs to.

Knowing which side is which matters for practical reasons. Dates are read from the obverse, and grading services describe surface condition separately for each side, so a coin can be noticeably nicer on one face than the other. Mint mark placement is series-specific and appears on the obverse of some coins and the reverse of others.

When you describe a coin to a dealer over the phone, saying obverse and reverse rather than front and back removes ambiguity.

Texas Bullion Exchange offers free appraisals if you want help identifying what you have.