Organizing photo on iPhone (moving from PC to Mac)

Hiya guys,

I am finally taking the big step of ditching my windows PC and moving to an iMac, so count me as a total noob who is willing to learn.

Now, I used to keep a lot of photos I saved from the internet in a lot of folders on my windows PC. This is in turn imported into my iPhone with the pictures sorted nicely into the folders.

I am not really certain how I would do the same thing into the Mac though (as I said, total Mac noob).

Do I copy the photos via an external hard drive into my Mac documents folder, and then just ask iTunes to sync that?

Or should I put it all into the Photos app?

Is the Photos app meant to organize ALL images inside your Mac?

Would appreciate any input! Thanks!