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what is the difference between microcontroller & microprocessor?

A microcontroller (sometimes abbreviated µC, uC or MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.

A microprocessor incorporates the functions of a computer's central processing unit (CPU) on a single integrated circuit (IC, or microchip).[1] It is a multipurpose, programmable, clock-driven, register-based electronic device that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output.

During the 1960s, computer processors were often constructed out of small and medium-scale ICs containing from tens to a few hundred transistors. The integration of a whole CPU onto a single chip greatly reduced the cost of processing power. From these humble beginnings, continued increases in microprocessor capacity have rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessors used in everything from the smallest embedded systems and handheld devices to the largest mainframes and supercomputers.

The first microprocessors emerged in the early 1970s and were used for electronic calculators, using binary-coded decimal (BCD) arithmetic on 4-bit words. Other embedded uses of 4-bit and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc., followed soon after. Affordable 8-bit microprocessors with 16-bit addressing also led to the first general-purpose microcomputers from the mid-1970s on.

Since the early 1970s, the increase in capacity of microprocessors has followed Moore's law, which suggests that the number of transistors that can be fitted onto a chip doubles every two years. Although originally calculated as a doubling every year,[2] Moore later refined the period to two years.[3] It is often incorrectly quoted as a doubling of transistors every 18 months.

Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. Mixed signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems.

Some microcontrollers may use four-bit words and operate at clock rate frequencies as low as 4 kHz, for low power consumption (milliwatts or microwatts). They will generally have the ability to retain functionality while waiting for an event such as a button press or other interrupt; power consumption while sleeping (CPU clock and most peripherals off) may be just nanowatts, making many of them well suited for long lasting battery applications. Other microcontrollers may serve performance-critical roles, where they may need to act more like a digital signal processor (DSP), with higher clock speeds and power consumption.

First you have to know that what is microprocessor and what is microcontroller.

Microprocessor is a multipurpose, programmable,register based electronic device which read binary instructions from memory, processes the input data as per instructions and provides output.
Microcontroller is a device that includes microprocessor, memory and input/output devices on a single chip.

Comparison of Microcontroller and Microprocessor

Microcontroller
1. Microcontroller having inbuilt RAM or ROM and inbuilt timer.
2. Input and output ports are available.
3. Inbuilt serial port.
4. Separate memory to store program and data.
5. Many functions pins on the IC.
6. Boolean operation directly possible.
7. It take few instructions to read and write data from external memory.

Microprocessor
1. Do not have inbuilt RAM or ROM and timer.
2. Input and output ports are not available, requires extra device like 8155
3. Do not have inbuilt serial port, requires 8250 device.
4. Program and data are stored in same memory.
5. Less multifunction pins on IC.
6. Boolean operation is not possible directly.
7. It take many instruction to read and write data from external memory.

I'm giving you the simple difference between Microprocessor and Microcontroller. See the notes below. They are easy to understand.

Microprocessor = cpu
Microcontroller = cpu + peripherals + memory
Peripherals = ports + clock + timers + uarts + adc converters +lcd drivers + dac + other stuff
Memory = eeprom + sram + eprom + flash

A microcontroller has a combination of all this stuff.
A microprocessor is just a CPU .

Some of them are 8051, 8255, 8253/8454(timer), 8279(keyboard/display controller).

Hope, this information may be sufficient to you.

What is the based system of microprocessor