Tablature (or 'tab' for short) is the most popular way of writing music for guitar. It's like a map, showing you which strings and frets to play.
Reading tab is like looking down at the strings on your guitar. The thickest string is nearest to you, and the thinnest one is furthest away.
Each note has a number that tells you which fret to play: 1, 2, 3, and so on. '0' means to play a string open (without holding any frets down).
In Yousician, the color of the note tells you which finger to use. Check out the little hand to see how it works.
In Yousician, we write chords as blocks that show you when to strum.