There are several types of computers: - Super computers are the fastest and most powerful computers used for weather forecasting, aircraft design, and are very expensive. Examples include CRAY1 and CRAY-2. - Mainframe computers are expensive servers used on the internet. An example is IBM S/390. - Mini computers are used for business, government, education, hospitals, and as servers in network environments. Examples are AS/400 and prime computers. - Micro computers include desktops, laptops, workstations, networks, and handheld devices used in homes and offices. They are handy and portable.

1. CLASSIFICATIONS OF COMPUTERS
Super computer
• weather forecasting,aircraft design
• Fastest ,powerful,expensive
e.g. CRAY1,CRAY-2
Mainframe Computers
• Expensive, server in www
e.g. IBM S/390
Mini computer
• Business,government,education,hospital,server in n/w environments
e.g. AS/400,prime computers
Micro Computers(desktop,laptop,workstation,network,handheld)
• Used in homes, offices
• Handy & portable

2. INTRODUCTION TO C

3. • Developed by Dennis Ritchie
• American National Standards Institute approved C in 1989 – ANSCI C

4. Characteristics of C
• Robust Language
• Combines the feature of assembly & highlevel language
• High level programming language (no worry about the machine code)
• Small size (32 keywords)
• Suited for structured programming
• Quick Language(make use of operators and datatypes so fast and efficient)
• Facilitates low level programming
• Portable language

5. Structure of a C Program
Preprocessor directives -> special instructions that indicates how to prepare program for compilation
Global declaration
main()
{
Local declaration
Statements
}
Function 1()
{
Local declaration
Statements
}
……………….
Function n()
{
Local declaration
Statements
}
include --- preprocessor command tells
compiler to execute some information is
needed from specified headerfile.
Function ---- group of c statements that are
executed together
Header file ---in built functions
int main ---return integer value to os
#include <stdio.h>
int main()
{
printf(“n welcome to the world of c”);
return 0;
}