microprocessors

• DRAM

Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit.
http://en.wikipedia.org/wiki/DRAM

• SDRAM

Synchronous dynamic random access memory (SDRAM) is dynamic random access memory (DRAM) that is synchronized with the system bus. Classic DRAM has an asynchronous interface, which means that it responds as quickly as possible to changes in control inputs.
SDRAM has a synchronous interface, meaning that it waits for a clock signal before responding to control inputs and is therefore synchronized with the computer's system bus
http://en.wikipedia.org/wiki/SDRAM

• SRAM

Static random-access memory (SRAM) is a type of semiconductor memory that uses bistable latching circuitry to store each bit.
The term static differentiates it from dynamic RAM (DRAM) which must be periodically refreshed.
SRAM exhibits data remanence, but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered.

• Data remanence

Data remanence is the residual representation of data that remains even after attempts have been made to remove or erase the data. This residue may result from data being left intact by a nominal file deletion operation, by reformatting of storage media that does not remove data previously written to the media, or through physical properties of the storage medium that allow previously written data to be recovered
http://en.wikipedia.org/wiki/Data_remanence

• Transistor–transistor logic

Transistor–transistor logic (TTL) is a class of digital circuits built from bipolar junction transistors (BJT) and resistors. It is called transistor–transistor logic because both the logic gating function (e.g., AND) and the amplifying function are performed by transistors
http://en.wikipedia.org/wiki/Transistor-transistor_logic