Copy & Paste Text Only without an editor:

I know how to empty a file at the command line,
cat /dev/null > /MyRecords
but I don’t know how to do this:

Select text from another file at the command line: /MyNotes

then paste into: / MyRecords

I know how to do a simple copy but I don’t want to copy the file. I need to do it the way described above.
For years, I don't know why but I use to get a warning when I hit the Thanks button:
WARNING: "Are you sure you want to proceed"

I click, heck NO! and never tried again to often. I think its a social media thing. I'm not into Facebook and such, because if I get track I'm never get a job for being a dumb-a with all my question that many did not understand, or I have problems trying to grasp a simple reply that works.

So I say Thanks and I mean it.

Thanks Phishfry, Now I know what cat really mean.... see what I mean