The baritone ukulele is the largest sized ukulele. It was created last of all the the other types of ukuleles, around the 1940's. The length is 30 inches, a full nine inches longer than the smaller soprano ukulele. It comes with four strings usually, but can be custom built to have more strings. It produces the fullest sound out of all the ukuleles and is said to resemble a small guitar. The price range is higher than all the other ukuleles.
The part of the ukulele instrument called the scale refers to the length where the strings can be played. Usually, it runs from the top peg to the bridge of the ukulele. This length differs amongst the four standard types of ukulele. The soprano, with a 13" scale, is the smallest. The baritone, with a 19" scale, has the longest playable area of all the ukulele types. This gives the feel of a small guitar instead of a ukulele.
The baritone type of ukulele can be tuned just like the four top strings of a guitar. If you already know how to play the guitar, learning to play the baritone will be easy for you. Although the typical arrangement for the strings of a ukulele is a G-C-E-A arrangement, this can cause the strings to be tightened too much on a baritone instrument. This can cause damage to the ukulele. For that reason, many people who choose a baritone will tune it to a D-G-B-E arrangement, which is why it is similar to the top four strings of the guitar.
To make a decision on what type of ukulele to buy, you will have to factor in cost plus your level of musical ability and interest in playing. If you already know how to play the guitar, a baritone ukulele can be a quick way to get up to speed with a new instrument using what you already know.
This instrument is costlier than a soprano, but if you know you already have skills in this area it can be well worth the investment. Otherwise, you might want to stick with a cheaper soprano or concert ukulele while you learn.