Some definitions...

CPU:It is the microprocessor, also known as the intelligent card.
RAM:Random Access Memory, it is  volatile memory which means that when the power is turned off  it will lose the data that is stored.
ROM:Read Only Memory. Permanent memory which means the when power is turned off it will not lose the data that is stored .
DRAM:Dynamic Random Access Memory, it is similar to RAM, but it requires a periodic refresh from the CPU for it not to lose the data that it stores .
SRAM:Static Random Access Memory. Classical RAM memory it does not need to be periodically refreshed by the CPU.
EPROM:Erasable and Programmable Memory. Permanent memory that can be erased and reprogrammed with the right tools.
FLASH:Specific type of EPROM that can be erased and reprogrammed by the CPU using the appropriate SW.
RTU:Remote Terminal Unit. Peripheral for automation and control systems.
SCADA:Supervisory Control and Data Acquisition. Main unit for the supervision, control, and acquisition of data.
Field Bus: Data communications medium used in automation and process control industries, connects the main controller to it peripheral.
Firmware:It is the SW that runs on a microprocessor card.
Real-Time:A system that is able to handle and respond in real time situation to asynchronous signal from itís surrounding environment.
RTOS:Real Time Operating System, a distinct operating system used for real time applications.
Debugger:A tool used to verify the correctness of the SW.  In an embedded environment it will run on a host computer which then has a physical connection with its target, allowing the FW to be debugged.
TCP/IP:Transmission Control Protocol/Internet Protocol. A Protocol that creates a reliable connection (ie. architecture CLIENT/SERVER )between process so that it can exchange data streams.
UDP/IP:User Datagram Protocol/Internet Protocol. It allows the the exchange of packets (datagram) without the need of fixed connection.
ARP:Address Resolution Protocol. Protocol that utilizes a network (ie.  Ethernet) to resolve the actual address of the host and the IP address.
SNMP:Simple Network Management Protocol. Protocol used to handle TCP/IP networks.
FTP: File Transfer Protocol. Protocol used to transfer files over a network.
NFS: Network File System. Distributed file system connecting  various computers on a network.
SLIP: Serial Line Internet Protocol. . Internet connection using the TCP/IP protocol with a serial line (Modem connection).
PPP: Point to Point Protocol. Internet connection using the TCP/IP protocol slightly faster then a SLIP connection.
Embedded environment: HW & SW environments for the design and development of firmware.