A headphone port refers to the place on a device, like a computer or phone, where you can plug in your headphones. It allows you to listen to audio without disturbing others around you.
The bottom plays host to the USB - C charging port, while you'll find a 3.5 mm headphone port on the top. (techradar.com)
There doesn't seem to be a 3.5 mm headphone port on the top or the bottom, so be prepared for that possibility. (xda-developers.com)
That's not much of a surprise in a budget phone, but you will definitely want to use the 3.5 mm headphone port for listening to music or enjoying movies. (techradar.com)