Pass WGU D386 – Complete Study
Guide + Practice Pack (2026)
• Know the functions of a CPU as well as ALU, CU, registers, and pipelining.
- CPU: Comprises of ALU(arithmetic/logic unit) and CU(control unit)
- ALU: The arithmetic/logic unit(ALU) is the component of the CPU where data is help
temporarily and where calculations take place. It corresponds directly to the calculator
in the Little Man Computer.
- CU: The control unit(CU) controls and interprets the execution of instructions. IT follows
a sequence of actions that correspond to the fetch-execute instruction cycle.
- Registers: Is a single, permanent, storage location within a CPU used for a particular
defined purpose. A register is used to hold a binary value temporarily for storage, for
manipulation, and/or for simple calculations.
- Pipelining: Fetching a new instruction while the previous one is still completing
execution, similar to processing on an automobile assembly line.
• Know the functions of RAM and the different levels of cache. L1 cache, L2 cache, and L3 cache
memory. You also have Virtual RAM and you should know that as well.
- RAM: RAM is an acronym for Random Access Memory. It is a slight misnomer since
other types of semiconductor memory can also be accessed randomly.
- Volatile RAM: Volatile memory loses its contents when power is removed or when PC is
turned off.
- Non-Volatile RAM: Non volatile memory retains its values even when power is removed.
- Cache Memory: Cache memory is organized into blocks. Each block provides a small
amount of storage, perhaps between 8 and 64 bytes also known as cache line. Cache
memory is small compared to main storage and also has a speed advantage beyond the
use of faster memory technology.
- L1 Cache: If the requested memory is located in L1, the instruction is immediately read
into the CPU. It is the smallest and the fastest cache.
- L2 Cache: If the instruction in not present in L1 Cache, the request is passed on to the L2
Cache. L2 works exactly the same way as L1 Cache. If the instructions are found in L2, it
is passed on to L1 then to the CPU. L2 cache is larger than L1 and a little slower.
- L3 Cache: Same as L1, if instructions is not found in L2, then the technique can be
extended to more levels such as L3. It is larger than L2 cache and is the slowest out of L1
and L2. It is also shared among all processor cores.
- Dynamic RAM: Less expensive and requires less electrical power. Generates less heat
and can be made smaller.
- Static RAM: Static RAM is faster to access than dynamic RAM therefore it is useful in
very-high-speed computers and small amounts of high-speed memory, but static RAM is
lower in bit density and more expensive.
, • Know the functions of the motherboard and know the difference between ATX vs Mini ITX. Also
know what expansion slots are, memory slots and cache, northbridge, and southbridge.
- Motherboard: In most computers, the CPU, memory, and other major components are
mounted to a wiring on a printed circuit board known as a motherboard. The wiring on
Guide + Practice Pack (2026)
• Know the functions of a CPU as well as ALU, CU, registers, and pipelining.
- CPU: Comprises of ALU(arithmetic/logic unit) and CU(control unit)
- ALU: The arithmetic/logic unit(ALU) is the component of the CPU where data is help
temporarily and where calculations take place. It corresponds directly to the calculator
in the Little Man Computer.
- CU: The control unit(CU) controls and interprets the execution of instructions. IT follows
a sequence of actions that correspond to the fetch-execute instruction cycle.
- Registers: Is a single, permanent, storage location within a CPU used for a particular
defined purpose. A register is used to hold a binary value temporarily for storage, for
manipulation, and/or for simple calculations.
- Pipelining: Fetching a new instruction while the previous one is still completing
execution, similar to processing on an automobile assembly line.
• Know the functions of RAM and the different levels of cache. L1 cache, L2 cache, and L3 cache
memory. You also have Virtual RAM and you should know that as well.
- RAM: RAM is an acronym for Random Access Memory. It is a slight misnomer since
other types of semiconductor memory can also be accessed randomly.
- Volatile RAM: Volatile memory loses its contents when power is removed or when PC is
turned off.
- Non-Volatile RAM: Non volatile memory retains its values even when power is removed.
- Cache Memory: Cache memory is organized into blocks. Each block provides a small
amount of storage, perhaps between 8 and 64 bytes also known as cache line. Cache
memory is small compared to main storage and also has a speed advantage beyond the
use of faster memory technology.
- L1 Cache: If the requested memory is located in L1, the instruction is immediately read
into the CPU. It is the smallest and the fastest cache.
- L2 Cache: If the instruction in not present in L1 Cache, the request is passed on to the L2
Cache. L2 works exactly the same way as L1 Cache. If the instructions are found in L2, it
is passed on to L1 then to the CPU. L2 cache is larger than L1 and a little slower.
- L3 Cache: Same as L1, if instructions is not found in L2, then the technique can be
extended to more levels such as L3. It is larger than L2 cache and is the slowest out of L1
and L2. It is also shared among all processor cores.
- Dynamic RAM: Less expensive and requires less electrical power. Generates less heat
and can be made smaller.
- Static RAM: Static RAM is faster to access than dynamic RAM therefore it is useful in
very-high-speed computers and small amounts of high-speed memory, but static RAM is
lower in bit density and more expensive.
, • Know the functions of the motherboard and know the difference between ATX vs Mini ITX. Also
know what expansion slots are, memory slots and cache, northbridge, and southbridge.
- Motherboard: In most computers, the CPU, memory, and other major components are
mounted to a wiring on a printed circuit board known as a motherboard. The wiring on
