OLAP - Online Analytical Processing, which deals with
analysis of data. It has to deal with historical data too (
for analysis purpose) Not updated frequently. If required
bulk update is allowed. 

OLTP - Online Transactional Processing, which deals with
transactions. For e.g. withdrawals at ATM machines. It
involves many transactions. The databases have to be updated
more frequently after the successful completion of a
transaction.

i am agree with the above answer.olap is denormalized and
oltp normalised

OLTP 
* Is the E-R modleling,there are more concurrent users,
* It contains normalized tables so there is no redundancy.
* More tables,Joins and less Indexes,
* It stores daily transactional data
* It stores very less data 
* It contains mainly current data
* INSERT,UPDATE,MODIFY can be applied on OLTP.
* Performace will be high

OLAP
* It is the Dimensional Modeling
* It contains Denormalised  tables there will be redundancy.
* Less tables,Joins and more Indexes
* It stores operational data
* It contains Historical and Present data
* only SELECT clause is applied on OLAP
* It stores very Huge data
* Performance will be low compared with OLTP

OLTP 
 
•	Current data 
•	Short database transactions 
•	Online update/insert/delete 
•	Normalization is promoted 
•	High volume transactions 
•	Transaction recovery is necessary 
•	 only one record is processed at a time
•	data is present in 2d format
 
OLAP 
•	
•	Current and historical data
•	Long database transactions 
•	Batch update/insert/delete 
•	Denormalization is promoted 
•	Low volume transactions 
•	Transaction recovery is not necessary
•	group of records processed at a time
•	data is present in multi dim format