Arduino: The Arduino is defined as an open-source electronics prototyping platform based on flexible, easy-to use hardware and software. It’s intended for artists, designers, hobbyists, Arduino enable users to read inputs from a sensor, a finger on a button, or a Twitter message - and turn it into an output - activating a motor, turning on an LED, publishing something online. All this and more can be done by a set of instructions programmed through the Arduino Software (IDE).

Microprocessor: The microprocessor (denoted as µP) is an integrated circuit that is contained in a single chip, it performs the central processing and internal functions of the computer, the µP is the dominant controller in the computer, it governs and synchronizes all the task in the machine, the µP is a high speed chip, sometimes it is called CPU (Central Processing Unit), it can be classified based on many properties such as speed, internal structure, address buss number (which is an old classification).

Microcontroller: The microcontroller (denoted as µC) is a single chip integrated circuit that is designed to function as an embedded system (contains a CPU, RAM, ROM, ADC’s, I/O ports and timers), the µC’s are intended for controlling user designed applications not computers, the µC also can synchronize its tasks, the applications that µC can control depends on its size, and as in the µP, µC can be classified based on many properties such as speed, internal structure, size/type of internal memory, Input/output number, sometimes the µC is called (computer in chip) because external components used in µP are embedded (build in) in the case of µC, so µC almost does not need an external components to make it work.

Circuit: it is a set of electronic or electrical elements that are connected together in order to perform a specific task, circuits may be simple or complex, programmable or non-programmable. (Note that every electronic element is electrical, but not every electrical element is electronic)

Integrated circuit: sometimes it is called “circuit in chip” and denoted as IC, it is an electronic circuit that is built in a tiny scale (microscopic scale) and contained in a plastic casing (enclosure) to protect it and ease using it, the circuit consists of semiconductor elements (diodes, transistors) usually, it contains also another elements such as resistors and capacitors, these circuits are classified mainly based on their size to: small scale ICs (SSI), medium scale ICs(MSI), large scale ICs(LSI), very large scale ICs (VLSI), very very large scale ICs (VVLSI).

Resistor: it is the simplest electronic element, it is an element that restricts (resists) the current flow in the circuit in order to reduce the power consumption in the circuit and protect other electronic elements in it, it is measured in (Ohm), resistors have a wide range of values, they are also classified based on many properties, technically, any object is considered to be a resistor, even the table you are setting on while you are reading this definition! But keep in mind that the resistor values start from zero Ohms to several GegaOhms.       

Capacitor: it is an electronic element aimed for storing electric charge, it can be charged and discharged repeatedly, it can be discharged very fast (portion of a second) or very slowly (minutes or even hours) unlike the batteries that needs a longer time to do either of the two operations, this element has many types, in general, this element is used in timing and memory circuits.

Diode: it is very popular electronic element, it belongs to what is known as pn devices (also known as two terminal devices), it is consisted of two semiconductor layers in which one of them is processed (doped) with negative charged material and the other is processed (doped) with positive charged one, this element is constructed to allow the current flow in the circuit in one direction only, so it is used in protection circuits, diodes have many types, but all of them share the property of current direction control.

Transistor: it is the most commonly used basic element, all the technical modern word owes this element because it is the one that made the ICs manufacturing possible, the transistor has many structures but all of them are made from semiconductor materials arranged in form of layers or substrates, the main objective of the transistor is to perform as a switch, a controlled switch, but the significance of the transistor is because it allow us to construct very large circuits in a small size such as computer CPUs (for example, a Pentium 4 CPU contains 100,000,000 transistor).

Frequency: physicists define the frequency as the number of waves occurred during one second, its unit is (1/second) which is called Hertz (Hz), in a non-physical terms, frequency can be defined as the number of repetitions for an action during one second, for example:

If you move your hand 3 times per second, then the frequency is said to be 3Hz.
If a pendulum moves 10 times per second, then the frequency is said to be 10Hz.
If a wheel rotates 20 complete rotations in one second, then the frequency is said to be 20Hz.

Open-source structure: this is a continuously growing concept; it means that the structure details can be shared with every one such that anyone can freely republish or modify the structure according to the user’s demands without any restrictions, this structure may be anything such as:

  • Software: such as programming software (such as Arduino IDE).
  • Hardware: any hardware may be open-source, such as robots, circuits; even some building constructions may be open-source.    

ICSP: it is an abbreviation for (In-Circuit-Serial-Programming), it is also known as ISP (In-System-Programming), it one of the programming methods used to program programmable logic devices, µC and any other embedded devices, as the name implies, in this method you can program the device while it is still connected to the circuit (the application circuit), and it does not require to remove the µC to an external programming circuit.

Programming Language: it is an interfacing environment that is used for interacting with the µC, µP or PC or any other programmable device, this environment includes a set of instructions that make us able to tell the machine (programmable device) what to do, control its actions and describe these actions for the machine, programming languages are divided into three levels:

High-Level programming Languages
Assembly programming Languages
Low-Level programming Languages

In fact, some references divide programming Languages into 2 levels considering the Assembly Languages as a Low-Level Languages, but it is more accurate to divide into three levels.