If you play using sheet music, you'll most likely run into "musical road signs," or symbols that make you jump to various parts of the music. The purpose of these road signs is simply to avoid repeating large chunks of the written music and thus allow for much more music to fit on a page.
Following are the most common road signs you'll see when following along with sheet music. They may seem confusing at first, but eventually you'll grasp them as easily as following a real road map and know when to turn left or right.
Repeat signs
Sometimes you'll see a symbol in music called a repeat sign. When you see this symbol, which looks like a colon followed by a straight line, you should go back to the symbol that mirrors the repeat sign (same symbol, just backward). This is written to extend the music and not to have to rewrite the same exact musical line twice.
First and second endings
Sometimes you'll find situations where you see a first and second ending in a song. The first bracket is the first ending of a section, and the second bracket is the second ending. You play either the first or second ending when you play the piece, but never one after another. By choosing the first ending, you play the music under the first ending bracket and then repeat to a certain spot (every first ending has a repeat). When you get to the first ending again, you skip the first ending and then play the second ending. You never play the first and second endings consecutively.
So why would you choose to play either the first or second ending? In the case that you want to play a song for as long as possible, playing the first and second endings is appropriate. Sometimes in a fiddle piece, the song is so short that it makes sense to always play both endings. However, you may want to just play the second ending in a piece to get through it quickly. Because taking both endings requires a repeat, sometimes you may want to avoid that (like when you're in a hurry!), and in that case, you just play the second ending.
D.C. al Fine
Sometimes when you reach the end of a fiddle piece, you'll find another element of music — the term D.C. al Fine. This means that you should restart at the very beginning of the piece and end when you see the word "Fine."