Grand, Upright, or Electronic?
Grands have certain advantages over uprights. However, these advantages are minor compared to the importance of the skill level of the pianist. There are great pianists who became technically advanced practicing mostly on uprights. There is no evidence that you need a grand for initial technical development, although a few piano teachers will insist that any serious student must practice on a grand. An argument can be made in favor of uprights, at least for beginners, because uprights require firmer playing and may be better for early finger development (you need to press harder in order to make louder sounds). They may be superior even for intermediate students because uprights are less forgiving and require greater technical skill to play. These arguments are controversial, but do illustrate the point that, for students up to intermediate level, any differences among uprights and grands are small compared to other factors such as student motivation, talent, quality of teachers, practice methods, and proper piano maintenance. Another factor is piano quality: good uprights are superior to low quality grands (which includes most grands under 5.2 feet). In general, students above intermediate level will need a grand piano.
Electronic (also called digital) pianos have capabilities that the acoustics (the mechanical uprights and grands) cannot provide and therefore fill a niche of their own, as explained below. They cost much less, are easier to purchase, maintain and transport, and make excellent starter or second pianos. The electronics have basically rendered the uprights obsolete. Therefore, if you are buying your first piano, it is easiest if you start with a quality electronic and then purchase a grand later on, when you are certain that the piano is going to be a big part of your life. Thus the rule concerning uprights is simple: if you already have one, there is no reason to get rid of it until you buy an electronic or a grand; if you don't have a piano, there is no compelling reason to buy an upright.