database is there easier way then this?

Hello all,
I'm just trying to get pointed into right direction.
I am stuck and any advice appreciated.

Building API (new to backend) for practice that retrieves thousands of images and each image has details such as
name of image
id
year
description

Is there anyway to automate it or map it?
Or do i have to enter each image and details by hand :S

take STAMP.io for instance how did they add hundreds of thousands of stamps with details surely not by hand or did they just import existing databases?

thank you any books or topics appreciated.