Hi, Zenjou S.
Artificial Intelligence and Expert System
Artificial Intelligence is a general term for computer systems that behave in human-like ways. There are a variety of technologies applied in the field, many of which are used for Machine Learning (a system which automatically learns, by some means, to behave in human-like ways).
Expert Systems can be seen as such a technology, excepting that expert systems are usually driven by a set of rules built by a domain expert (hence, the name), so rather than automatically learning, the system is 'taught' by the rule-set created by the expert.
EDSAC and EDVAC
The [E]lectronic D[escrete] V[ariable] A[utomatic] C[omputer] (EDVAC) was an early, binary electronic computer, delivered in 1949. It was built for the U.S. Army's Ballistics Research Laboratory at the Aberdeen Proving Ground by the University of Pennsylvania's Moore School of Electrical Engineering, by John Mauchly and J Preser Eckert, along with John von Neimann and other engineers from the previous ENIAC project. Von Neumann's monograph on the EDVAC proposed an enhancement in which the program to be executed would be stored in the same memory as the data. This "stored program" concept, now called the Von Neumann architecture, is the basis for nearly all electonric computers, today.
The E[lectronic] D[elay] S[torage] A[utomatic C[alculator] (EDSAC) was inspired by Von Neumann's "A First Draft of a Report on the EDVAC", and was the first stored program electronic computer. It was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England.
System Programmer and Application Programmer
A Systems Programmer, generally, creates the software which acts as a layer between applications running on a computer, and the resources of the computer (including CPU, memory, and I/O); they write the 'system' software, including operating system(s), device drivers, etc. In effect, the systems programmer help to hide the details of the hardware and operating system from application programs.
An Application Programmer, generally, writes software for user-specific purposes.
Information Technology and Information System
Information Technology is the wide variety of hardware, software, and processes used for the purpose of collecting, preserving, and analyzing data, for the purpose of reporting information (especially Business information) about the data.
An Information System is an embodiment of Information Technology that is used to collect, preserve, analyze, and report information (from data).
Transistor and Vacuum Tubes
Transistors and vacuum tubes are 2 kinds of electronically (i.e., non-mechanically) controlled switches. An example of a mechanically controlled switch is a relay. All 3 have been used to build computers, beginning with relays (the slowest with times in 10e-1 seconds, and generally the biggest on a scale of 10a-2 meters) and ending with transistors (by far both the fastest with times in 10e-9 seconds, and smallest at 10e-9 meters).
Transistors are made with a semiconductor material, 'doped' so that part has extra electrons, and part has extra 'holes' (missing electrons), and typically 3 connections: the base, emitter, and gate. A vacuum tube looks similar to a light bulb, also typically with a base, emitter, and gate. From a logic perspective, they both perform the same job in a similar way. Vacuum tubes were often 1 tube = 1 switch, although some larger ones held multiple switches (and other similar devices). Transistors were originally contained in small (< 1cm) 'cans' per switch, and now are built by the billions on a single piece of silicon (billions in < 1 cm^2).
Hardware and Software
Hardware refers to the physical component(s) (CPU, memory, I/O and storage devices, etc.) of a computer, i.e. everything that you can see and touch.
Software refers to the program(s) and data which are preserved inside the computer (e.g. on disks and in memory), and which cause the computer (hardware) to perform task(s).
