Short-term investment I think the duration is under one year and long-term investment the duration is over one year.
No that's a mid term investment.
Long term is usually 5 years if you pushing it and normally above 10 years.
Short term holders?
Guess that's a fancy way of saying Long term traders.
HODLING means despite the rain and sun and storms you ain't moved by the market to sell your holdings.
The phrase you said is actually quite reasonable for most people to understand because currently there are still those who consider themselves short term holders, even though such people are more suitable to be called long term traders because they still make a target to sell it back in a not so long time even though we can make every time setting to hold it ourselves according to our own tastes. But for long term Bitcoin holders, they usually hold it for close to ten years or more than five years to see how much profit they can get from it.