I want to know the web security concerns associated with letting the users upload photos in my websi

I am a web designer. I know php. My website is hosted with a hosting company.

I want to know the web security concerns associated with letting the users upload photos in my website?

you%26#039;ll need a directory with write permissions to be able to upload. with your upload code or module, you can limit the file type and size. just make sure to designate a special folder for it, don%26#039;t put it in the root directory or something