Piano manufacturers design their products according to the needs of a particular venue or performer. A professional concert pianist playing with a full orchestra might need a full-sized concert grand piano, while an accompanist for a small church may only need an upright piano. There are other gradations along the way, and even some electronic elements to consider.
The largest type of piano is called a concert grand. This type can often be found in recital halls and orchestral stages. Because of its size and tuning requirements, musicians usually go to the piano rather than the other way around. Concert grand pianos generate very vibrant tones, especially in the lower registers. This is important when a solo pianist must compete with a full orchestra.
For most people, the largest practical size of piano is either a grand or a baby grand. These use the same horizontal soundboard configuration as a concert grand, but are not nearly as long. A typical grand piano is about 3/4 the size of a concert grand, and a baby grand is about 1/2 the size. Both use a hinged lid to direct the sound towards the audience during performance. Many schools of music keep several grands and baby grands available for student recitals or for visiting performers.
For home use, many amateur pianists select upright pianos. These use vertically mounted strings to significantly reduce horizontal length. This means that an upright piano can be installed in a living room or den without taking up any more room than a couch or bookcase. The sound of an upright may not be as full as a grand, but it is perfectly suitable for informal performances. Many upright pianos are handed down from generation to generation.
Some pianos also come equipped with pick-ups and amplifiers to create an entirely new sound. Electric pianos first became popular with jazz musicians, because the pianist could duplicate the solo breaks of a guitarist along with the chording of a piano. These instruments can also be carried on the road without the detuning problems of a traditional piano, many traveling bands use electric pianos and synthesizers almost exclusively.
Some people learning to play may encounter rehearsal pianos with a limited number of octaves. These are mostly intended to accompany music theory classes or for basic keyboard courses. Some recent do-it-yourself piano courses even include a very small electronic keyboard which can be rolled up and stored between sessions.