Hello Shashank,

You havent mentioned any board name so I'm assuming you are talking about NCERT if not please specify.

There are in total 11 chapters for computer science which are further divided into smaller units.

The first chapter  Computer System is divided into 8 units as follows

1.1 Introduction to Computer System

1.2 Evolution of Computer

1.3 Computer Memory

1.4 Data Transfer between Memory and CPU

1.5 Microprocessors

1.6 Data and Information

1.7 Software

1.8 Operating System

Hope that helps you