99say wrote: …i only have copied the photos library to my external drive to save the photos and i am not going to be using it in the photos app, …, will i need some specific format or is it fine just copying over as i have done to backup the photos?
A Photos Library is really only usable by the Photos app. You can get some information about how Photos works here:
Basic Concepts and Terms About Photos - Apple Community
As that article says, Photos generates pictures from the Original picture files and the information stored in the database. This information can make a variety of different pictures. So when you say "save the photos," you'll have to decide which versions of these pictures you want to save.
Another consideration is the organization of the pictures. Do you have your picture in Albums and Folders? That organization is understood only by Photos. How will you organize these saved pictures?
In Photos you can use File>Export to generate pictures in jpg format. When you use File>Export>Export Unmodified Originals, you can save pictures as they were originally taken, without edits, keywords, titles, or captions.

The "Moment Name" subfolder puts pictures together that were take about the same time, so there is some organization provided. When you hit the Export button you get a dialog that lets you choose your external drive.
You can use File>Export>Export nn Photos, to save pictures with their edits and added metadata.

I have "Use Title" for the file name, but you may want to use the original filename, instead.
In Photos, when you see an edited picture, you can see just how you edited and cropped a picture, and you can change your mind about the edits. Outside of Photos, you can't do that.
I would not select all the pictures for export at once. If anything interrupts the export, like an incompatible format or a corrupt file, you may have to start all over again. I would do videos separately, since they are more likely to be a problem.
I wrote this earlier. It's pretty much the same stuff.
Saving Mac Photos to an External Drive for a PC - Apple Community