wget (tool for downloading files)
When you work on the command line, you have a full-featured Internet download manager at your fingertips: wget. Invoke the program like so:
This will download the file specified by URL to your computer. When a download is interrupted, you can resume it by specifying the option -c (“continue”):
wget -c URL
Call wget with the option -m (“mirror”) to create a local copy of a website:
wget -m URL
If you're curious about the many other features that wget has to offer, check out the program's excellent →man page.