There is a post, link will follow below, from the Raspberry Org site which is very informativ and handles how to connect your external hard disk, SSD, or USB stick to any of the USB ports on the Raspberry Pi(RPi), and "mount" the file system to access the data stored on it.
So there is no need for a rewrite and this post will therefore continue with how to connect to a Windows server, (Other SMB or Samba servers will also work), both temporary and automagically at boot.
Check this post RPi booting from an USB drive !