How can we Schedule batch apex in Salesforce?

How to create Apex Batch Class:

Create an apex class which implements Database.Batchable interface and class must be globle like mentioned below.
global class batchExample implements Database.Batchable
{

}

It is used to run large jobs (think thousands or millions of records!) that would exceed normal processing limits.

1- We can fetch 200 records in execution.
2-The main diff between Batch apex and scheduled apex is No of Records.We can only have 100
scheduled Apex jobs at one time, while for batch apex the limit is 200.
3-When we want to run a piece apex code at some particular time within a period of time.Schedule
apex is class which runs at a regular interval of time. To schedule an apex class we need to
implement an interface Schedulable.