A Motherboard is a Printed Circuit Board (PCB) for short. The Motherboard basically brings all the electronic components together. This allows all the components to communicate with each other. This makes the Motherboard the backbone of electronics.
Most PCB label their components with letters. Most common one are...
A Separable assembly
AR Amplifier
AT Attenuator; Isolator
B Blower, motor
BT Battery
C Capacitor
CB Circuit breaker
CP Connector adapter, Coupling
CN capacitor network
D or CR Diode
D or VR Breakdown diode
DC Directional Coupler
DL Delay line
DS Display lamp
E Terminal
F Fuse
FD* Fiducial
FL Filter
G Generator, Oscillator
GN General network
H Hardware
HY Circulator, directional coupler
J Connector, Jack, female
K Contactor, relay
L Coil, inductor, bead, ferrite bead
LS Loudspeaker, buzzer
M Meter
MG Motor-Generator
MH* Mounting hole
MK Microphone
MP Mechanical part
P Connector, Plug, Male
PS Power Supply
Q Transistor
R Resistor
RN Resistor network
RT Thermistor
S Switch
T transformer
TB Terminal Board, Terminal strip
TC Thermocouple
TP Test point, In-Circuit test point
TZ Transzorb
U Inseparable assembly, IC pkg
V Electron tube
VR Voltage Regulator
W wire, cable, cable assembly
X Fuse holder, lamp holder, socket
Y Crystal, magnetostriction oscillator
Z miscellaneous
The Components in Bold are ones you will find in a controller.
D Diode: A Diode allows the flow of current in only one direction
MG Motor-Generator: A Motor converts electrical energy into mechanical energy.
Q Transistor: for amplifying, controlling, and generating electrical signals
R Resistor: opposes the flow of current, employed to protect, operate, or control the circuit.
S Switch: used to control a circuit by either completing or breaking the circuit
Diode
Motor
Transistor
Resistor
Switch (Tact)