There are thousends of diffirect types of transistors. The number printed on them is usually the type number, not the make.
Diffirences between them are maximum voltage, maximum current, Hfe (amplification), package, size, power, speed, ... and many other things.
Though, for general applications there are some well known types wich have been around for ages and used by everyone. For small signals types like BC547 (NPN) and BC557 (PNP) are very common (europe).
... guess you will have to have an idea of what there going to be used for before you go buy them