I’m assuming you will be applying for PR using the Express Entry process. This process is an invite only process which means you have to be selected from a draw based on your total points. If selected you are invited to continue the process and gain PR.
Your file is kept in the pool for one year during which time there are multiple draws (selections) and you can be picked in any one of those. If say your points do not make the cut and you are not invited for a year then your file drops from the pool and you have to re-apply next year.
I hope this helps you understand that the process and that you can drop out of it at any point. Even after you’ve been selected to continue the application you can choose to not do that and re-apply next year. None of this will affect your future chances as the process is transparent and only based on your points.
If you do not respond to the Invitation to Apply by the deadline shown in your invitation, your invitation will expire and your profile will be removed from the pool. If you would like to be invited to apply again, you will need to create a new IEC profile. If you decline the invitation, your profile will become active again and you may receive another Invitation to Apply in the future.