if you literally mean "at the same time" you can use parallel - its a very usefull tool which provides you with ability to paralelize execution of several task or to execute a complex task in parallely. In you situation it would look something like this:

ls * | parallel --jobs +4 'cp {} /some_dir'

which means that parallel will take create 4 threads and every of them will try to copy one file piped from "ls" command

There are multiplse ways to accomplish this by the simplest is by using the sample script that goineasy9 has given.

If you wish to use more dynamic or network based functions your should look into xargs, find, rsync and scp.