Since scp seems to be covered...
The command for sftp should be 'sftp'. It works more or less the same as ftp but (at least in my experience) it has fewer conveniences, things like mput/mget, wildcard substitution and such. As always, check the man page.
I find sftp to be easier to use but I suppose if you become comfortable with scp it might be quicker, if you know exactly what/where you want to transfer.