Other than the motor, virtually all leaf blowers are made the same way. The motor turns a fan which blows high velocity air out of a tube. This air stream can be directed wherever the operator wants. It will blow leaves, cobwebs, standing water and even snow, cleaning or clearing the area of any debris or hazard.
Every leaf blower is powered by a small engine, so all are subject to the same problems when starting or running.
Always use fresh gasoline at all times, and if your leaf blower is a 2 cycle engine, make sure the mix is fresh too. If your gas is a season old, it needs to be drained and replaced with fresh fuel. Attempt to start it with fresh gas after the carburetor has been primed. This may fix the problem immediately.
If you have fresh gas, prime the carburetor per the manufacturer's directions, and pull the cord a few times. The blower motor should at least fire or 'pop,' and, if it doesn't, that generally means the spark plug is bad. Although spark plugs can be cleaned, they are so inexpensive that it is better to just replace them, and eliminate them as a potential cause of the problem.
Other things to check are fuel shut off valves, which if turned off, won't allow any fuel to get to the carburetor; the throttle, which needs to move into the choke position initially, or your blower won't start; and the emergency shut off handle or button, which needs to be grasped and/or pressed down or the blower won't start. Lastly, check the wire on the spark plug to make sure it is secure and tight.
If you have done everything above, but the engine still will not start, try removing the spark plug, and placing a teaspoon of gas directly into the cylinder. Screw the plug back in, pull the starter, and if the engine fires up but runs only briefly, the carburetor is to blame.
If you are handy at doing things yourself, purchase a carburetor rebuild kit to solve this problem. Otherwise, the engine will need to be taken into your local small engine repair person to be rebuilt.
One other carburetor problem can occur. If the engine runs at first but then leaks gasoline out of the exhaust when not running, you have a needle valve that isn't sealing properly. Once again, the carb will have to be rebuilt, but until that time and to stop the leaking, simply open the gas cap and allow the pressure to be released each time you use the leaf blower.