Batch is nothing but a set of sql statments that are 
executed at time (all the stmts will be exceuted or none(if 
any error encountered))

eg:
use [database]
GO
select empname from employee
insert employee(empno,empname)
select empno =1
,empname ='A'
GO

Batch in Sql server is a set of one or more Transact-SQL 
statements sent from a client to an instance of SQL Server 
for execution and it will represents a unit of work 
submitted to the Database Engine by users.