Using something like scp but when I've logged in already

I want to copy a file via ssh when I've logged in. What scp does is that it copies the files by login, password, path. What I want is to be able to do the same thing when I'm "inside", ideally without providing the login and password:

$ ssh root@123.123.243.63
root's password:

Welcome to .....
Last login: ....
root@folder1:~# // How do I download (or upload) the files when I'm here?