An information storage and retrieval system (ISRS) is a network with a built-in user interface that facilitates the creation, searching, and modification of stored data. An ISRS is typically a peer-to-peer network operated and maintained by private individuals or independent organizations, but accessible to the general public. Some, but not all, ISRSs can be accessed from the Internet. (The largest ISRS in the world is the Internet itself.)
Characteristics of an ISRS include lack of centralization, graceful degradation in the event of hardware failure, and the ability to rapidly adapt to changing demands and resources. The lack of centralization helps to ensure that catastrophic data loss does not occur because of hardware or program failure, or because of the activities of malicious hackers. Graceful degradation is provided by redundancy of data and programming among multiple computers.
The physical and electronic diversity of an ISRS, along with the existence of multiple operating platforms, enhances robustness, flexibility, and adaptability. (These characteristics can also result in a certain amount of chaos.) In addition to these features, some ISRSs offer anonymity, at least in theory, to contributors and users of the information.
A significant difference between an ISRS and a database management system (DBMS) is the fact that an ISRS is intended for general public use, while a DBMS is likely to be proprietary, with access privileges restricted to authorized entities. In addition, an ISRS, having no centralized management, is less well-organized than a DBMS.
As tasks are being performed on the computer, the need for storing the resultant information arises. The earlier sets of computers did not support starage but from the history of computer, we discovered that EDSAC (Electronic Delay Storage Automatic Computer) was the first to support storage. It was a landmark in computing. Storage devices we’re invented with recent developments in technology.
With the rapid development in the computer world, program became bigger than ever before. Since these programs are run on computers, they have to be in a place where they can be easily accessed. And tasks performed on computers need to be stored in one form or the other.
Generally, programs are written and stored in files. Just as school rules and regulations are written line-by-line and page-by-page.
Types of files
Files are normally stored as:
System files which allow the computer to work
Application files which are files from programs written to run on the computer for specific tasks.
Data files which are generated as a result of using application files or input.
These files differ in sizes according to the number of characters and graphics they hold (bjts and bytes).
Types of storage
There are basically two types of storage. They are the temporary and permanent storage media.
This refers to the unit of the system called the primary or internal memory. It resides in the CPU. It is termed the active memory. Any data coming into the system are temporarily stored in this medium. Information can easily be obtained from this medium by the system of processing.
If there is a power outage, or the system is shut down, the memory goes off and therefore every information therein is lost. The memory is also called Random Access Memory (RAM). It can store limited amount of information. Most computers also contain Read Only Memory (ROM), which can only be read, nothing can be written on to it.
Permanent storage, also external or secondary storage, stores information permanently. Information stored will not be erased from the memory even during a power outage.
Since the computer needs to store large quantities of data and the memory can only store limited amount of information, the permanent storage media which can hold a lot of information are, therefore highly needed. The necessary information can then be passed on the RAM where they will be processed by the microprocessor.