Unique Identification Authority of India (UIDAI) has activated a service on its website whereby anyone can verify details of any individual using their Aadhaar number. 

In a simple two step process, an individual can verify any number of Aadhaar numbers. 

Here's the process: 

1. Log in to uidai.gov.in 

2. Go to Aadhaar Services tab under Aaadhaar Online Services

3. Click on Verify Aadhaar Number

4. A new window will appear that will ask you to enter Aadhaar number and security code. 

5. Once you enter the two details, a window will appear that will tell you if whether the Aadhaar number exits with UIDAI or not. 

6. The website will also show you the age bracket that the person with that Aadhaar number is in. 

7. Other details like gender, state and last three digits of their mobile numbers will also be displayed on screen. 

One does not need an Aadhaar number of their own to verify any individual's Aaadhaar number or their identity. 

One can simply log in to the website and check whether the person who has given you their Aadhaar number checks out with the UIDAI database or not. Although the service is for citizens who already have Aadhaar numbers to check whether their Aadhaar numbers are active or not, there is another use of the service as pointed above.