Common repeat signs used in classical music are:
da capo - Symbolized by the letters D.C. and placed under the final measure. This means to repeat from the top or the beginning of the music piece.
dal segno - Also written as D.S., this means to repeat the measures starting from the segno sign.
da capo al fine - Sometimes a music sheet will bear the word fine under a measure. Da capo al fine means to repeat everything from the beginning ending with the measure with the word fine underneath.
Other repeat signs are used to signify that a measure or a number of measures needs to be repeated several times. These are called simile marks