How to prevent users from view other user profile or data ?

I have created 2 users (using devise gem) and added data in both the profiles, but both users can see each others data and profiles. How to stop users to access or see other users profiles

What does your controller look like for the action? You should be using the Devise helper method current_user.

For example, don't do this:

def show
  @user = User.find(params[:id])
end

Instead, do this:

def show
  @user = current_user
end