I have application form, where the form data will be stored in sp list. There are cases where a user can send more than one application form. If a user sends more than one application, we need to consider the lastly sent application, ignoring the old applications. How do I remove the duplicate elements and just display the items.
You have a few options: You can have a workflow created on item create which will delete previous items in the list deemed to be previous (based on name, ID etc).
Or you can add logic to your form where you do not permit submitting multiple application forms using validation (searching existing items).
Building on @Russell's answer, with Workflow you can do a number of things to address this issue:
1) Delete previous records by that user when a new one is submitted
2) Mark previous records by that user as old or deleted with a Yes/No column that you use to filter out by in your views.
3) Add a second list that service as an archive that you copy previous records to and then delete them from the main list.
If you don't want to do workflow to accomplish this, you could do some different types of custom views to make it easier to identify the newest record:
1) Sort the view first by user, then by created date descending. This will put the newest record by that user at the top.
2) Group the view by the user, then sort by created date descending. This accomplishes the same thing, however makes it easer to see the results separated by user.
Just some ideas for you.