Applications of Transistors with Different β values

[challarao]

Hi, I'm a newbie....
I came to know that there are many types of transistors available in the market with high, middle, and low β values.But, I don't have any idea about applications of each in detail.Can any body tell me the applications of high β, middle β, and low β valued CE transistors respectively.I think high β valued transistors are used as switches.Am I correct?.
Any help or web link would be highly appreciated.....
I tried searching in Google but couldn't find......
Thanks in advance.........

[es1]

Usually variation in B is due to optimizing some other variable. For example maybe you want to make a transistor that can carry a lot of collector current relative to other transistors, a very low temp co, or have a really high Vce breakdown voltage, etc.. These optimizations usually come with reduced B.

One can also sacrifice on the other variables of a transistor to maximize B. This is often done with low power (Ic<100mA) switches. Because of the high B one can manipulate Ic with very small amounts of power in Ib which is useful for switches.