For the home of a musician, the upright piano is usually the piano of choice. Grand pianos are designed to take up the stage at concert halls and deliver perfect sound three hundred rows from the stage, so they aren't generally an ideal home solution. Also, grand pianos cost a great deal more than upright pianos.
The current shape of the upright piano is first known to have been constructed in 1780. By 1802, Thomas Loud had refined the design by putting the piano strings in a diagonal formation. But the upright pianos of that time typically only had a few octaves. It wasn't until 1840 that the upright piano had 75 keys. By 1890 the upright piano had a full 88 keys, just like the grand piano. At this point, pianos had become more accessible, a complete alternative to the homes of serious musicians and students. They became a standard part of every pianist's home by the mid 20th century.
Upright pianos are typically categorized by height. The smaller piano at about 36? tall is known as the spinet. Pianos ranging from 42" to 44? tall are known as console pianos. Pianos 45" to 49? tall are called studio upright pianos. Any piano of at least 50? tall is referred to as being a full-sized upright piano. The reason these larger pianos are still made is that the general concept of piano string sound is that the longer your piano strings, the more full and large sounding the piano tone will be.
The feel of the upright piano is slightly different than that of a grand piano. This is because the strings help reposition each pressed key on an upright piano, while on grand pianos you must wait for gravity to takes its course. This may give the grand piano a slight string sound advantage, but for many people it gives the upright piano a definite feel advantage.
On the upright piano the soundboard and strings run up and down the height of the piano. The early pianos actually didn't take advantage of the height of upright pianos, have the string endings start at the keyboard level. This is why when you see old upright pianos from 200 years ago, they often have tall elaborate designs reaching high above the keyboard to cover the strings.
Upright pianos typically use one of the two major types of dampening systems to end note sounds. These two systems are not of equal value. The over damper system just doesn't do as well and many manufacturers have stopped using it. The way the over damper system works is by having the dampers covered in dampening material place at the top of the hammers. Conversely, the under damper system actually has the dampers sitting below the hammer level on the other side of the springs. This provides a sound difference that even untrained ears can pick up when both types of pianos are played side by side.
Traditionally, upright pianos have been done with the strings all running in parallel. An upright piano is referred to as being straight strung when the strings run in parallel. Many upright pianos now use what is known as the overstrung method. In this method the strings run two directions, instead of one direction, at different depth levels. This creates a formation like an X out of the strings. This method produces a richer tone because the strings can run the longer diagonal lengths of the piano rather than just the height of the piano.