The term “dedicated circuit” or appliance outlet is used in several different ways. Most commonly, it is used in reference to a phone or data line, or to an electrical circuit. In both cases, the idea is that a dedicated circuit is a circuit set aside for a specific use, often with the implication that the use is either sensitive in nature or highly demanding, making it necessary to isolate the circuit used. Such circuits require some extra attention and care during the installation phase so that they are installed properly given the use they are intended for.
A dedicated circuit is a circuit set up with its own circuit breaker and intended for a single use. In some cases, a receptacle may be wired to the circuit so that it can be connected to an appliance such as a stove or a refrigerator. In other cases, an appliance can be wired directly into the circuit, as is commonly seen with electrical water heaters.
While there should be three dedicated lines,quite often in older homes,there aren't. If you find that your kitchen appliances are tripping their circuit breakers--and it's not due to being older appliances--you may have to run a dedicated circuit to correct the problem.
Working inside an electrical panel can be very dangerous if you are not careful. While it is completely legal for homeowners to perform their own electrical work, if you feel uncomfortable, always hire an electrician to do the job.