# To download a single file
curl http://path.to.the/file

# To download a file and change its name
curl -o newname http://path.to.the/file

# To download multiple files
curl -O URLOfFirstFile -O URLOfSecondFile

# To limit the rate of a download
curl --limit-rate 1000B -O http://path.to.the/file

# To download a file and pass HTTP Authentication
curl -u username:password URL 

# To download a file from a FTP server
curl -u ftpuser:ftppass -O ftp://ftp_server/public_html/xss.php

# To download a file with a Proxy
curl -x proxysever.server.com:PORT http://addressiwantto.access