It is an RM065 100 Ohm Trimpot Trimmer Potentiometer.  The potentiometer is easy to mount on a PCB and can be adjusted using a screwdriver.

A ceramic capacitor is a fixed-value capacitor where the ceramic material acts as the dielectric. It is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes. The composition of the ceramic material defines the electrical behavior and therefore applications.

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

These resistors are typical axial-lead metal film resistors, which have much better temperature stability than their carbon equivalents which provides lower noise and are generally better for high frequency or radio frequency applications.

AMS1117-1.5V, 1A, Voltage Regulator IC is a series of low dropout three -terminal regulators with a dropout of 1.5V at 1A load current. AMS 1117 features a very low standby current 2mA.

AMS 1117 offers thermal shut down and current limit functions, to assure the stability of chip and power system. And it uses a trimming technique to guarantee output voltage accuracy within 2%. Other output voltage accuracy can be customized on demand, such as 1%

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

These resistors are typical axial-lead metal film resistors, which have much better temperature stability than their carbon equivalents which provides lower noise and are generally better for high frequency or radio frequency applications.

Small Size and light weight resistor which is suitable for both wave and reflow soldering leading to reduction in production costs.

0402 capacitor is Mounted either by flow or reflow soldering methods and gives excellent dielectric strength due to uniform structure of dielectric layers 

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

These resistors are typical axial-lead metal film resistors, which have much better temperature stability than their carbon equivalents which provides lower noise and are generally better for high frequency or radio frequency applications.

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

These resistors are typical axial-lead metal film resistors, which have much better temperature stability than their carbon equivalents which provides lower noise and are generally better for high frequency or radio frequency applications.

Small Size and light weight resistor which is suitable for both wave and reflow soldering leading to reduction in production costs.

0402 capacitor is Mounted either by flow or reflow soldering methods and gives excellent dielectric strength due to uniform structure of dielectric layers 

A ceramic capacitor is a fixed-value capacitor where the ceramic material acts as the dielectric. It is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes. The composition of the ceramic material defines the electrical behavior and therefore applications.

Small Size and light weight resistor which is suitable for both wave and reflow soldering leading to reduction in production costs.

In the instance of circuit failure or abnormalcy, with rising current, the increased current in the circuit may damage the device or important components or even burning of the circuit which may cause a fire. 

The fuse breaks the circuit if a fault in an appliance causes too much current to flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too much, the wire heats up until it melts and breaks the circuit. Thus play a role in the safe operation of the protection circuit.

Zener Diode is a special type of diode, which allows current to pass in the forward direction (from its anode to cathode) as well as in reverse direction (from its cathode to anode) after reaching Zener Voltage. This diode has a highly doped P-N junction. The difference between a normal diode and Zener diode is the voltage and sharpness of knee is well defined for a Zener diode but not for the normal diode. Zener diode can reliably work in breakdown region.This is a 1/2 Watt Zener Diode Voltage Regulator with tight limits and better operating characteristics that reflect the superior capabilities of silicon-oxide passivated junctions. All this is in an axial-lead, transfer-molded plastic package that offers protection in all common environmental conditions.

The 2N3906 transistor is commonly used as a switching device. When used as a switch, it can be operated in saturation region and cut-off region. In PNP transistor, by default it’s in ON state, but not to be said perfectly ON until the base pin is not grounded. If we provide ground to the base pin then the transistor will be in reverse biased and said to be turn ON. If supply is provided to the base pin it stops conducting current between emitter and collector and said to be in OFF state. For the protection of transistor a resistance added in series with it.