Optional field in admin panel to filter nodes in view Is there a way to add a optional field that filters nodes in a view?

I'm fairly new to drupal but I have a view that renders nodes depending on their categories. I can edit the view and manually add the filter but that affects all the nodes with that view. So is there a way to add filed to the "edit" screen of a page so I can have a field, that when filled it will filter the nodes it picks up and when it is empty it shows all the nodes?

Sorry if I'm using the wrong vocabulary, really new to Drupal
Not a problem... Drupal does have its own jargon but after a while you will get it.
Very simple solution whenever you want to offer user an option of refining the view or sort... Expose the relevant filter(s), in this case the vocabulary or taxonomy term... 
You might also think about using the global null function so as to reduce load on your server ... This will basically produce no results until the user chooses a vocabulary or taxonomy term (category)... Here is an excellent walkthrough on how to do this: How to prevent views from loading the results upfront

Cheers,
gg