Database

DATA:-Data is define as the representation of facts, concepts or instructions in a formalized manner suitable for communication , interpretation or processing by human or electronic machine . Data is represented with the help of characters LIKE alphabets(a-z,A-Z),digits(0-9)or special characters(+,-,/,<,>,etc).DATA FIELD OR ITEM:-A set of characters which are used together to represent a specific data elements are known as DATA FIELD OR ITEM.In the table the example of data field is ROLLNO, MARKSRECORD:-A record is a collection of fields or it is the row in a giventable that express a specific objects with their properties.INFORMATION:-The data that comes out after the processing on which the decision are take place is called INFORMATION.DATA PROCESSING:-The data processing is a process of converting a data into information on which the decisions can be taken. LIKE marks taken by a student on which he will be declare PASS or FAIL.DATABASE:-Database is collection of interrelated data i.e it is composed of collection of files that are linked in such a way that information from one file may be combine with information from other fileA database is also define as a collection of interrelated data stored together without harmful or unnecessary redundancy to serve multiple application.EXAMPLE:- A database of a given school may contain files or tables like about students, staff, funds etc.DATABASE has some following implicit properties1) A database represents some aspect of real world called miniworld. Changes to miniworld are reflected in database.2) A database is designed, built with data for specific purpose. It has an intended group of users.3) A database is a logically coherent collection of data with some inherent meaning.

routers

Routers are those connectivity devices that connect two different networks means they are used two form more bigger network by connecting two networks if and only if that two different networks have SAME PROTOCOLUnlike bridges router when connect two n/w it never make a single n/w means two n/w are connected and their address space is also different means they exists as two n/w’s (different) which are able to communicate with each other.But bridge when connect two n/w it form a one bigger means they have common address space means they have SAME NETWORK ADDRESS.Router also performs ROUTING which means to finding out BEST path when there are multiple paths exists between two hosts.