Crypto exchange - what do BTCUSD SELL and LTCBTC SELL mean? I just downloaded an app that forecasts the crypto market. The app seems to be nice but I don't understand the forecast interface. What does this mean?

BTCUSD SELL,  
LTCBTC SELL 


Does it mean that I can sell my bitcoin to someone that has dollars?

For the second, does it also mean that I can sell my LTC to someone that has BTC that is invariably buying BTC with LTC?
BTCUSD means you are selling your BTC in exchange of USD, same with LTCBTC, you are selling your LTC in exchange of BTC. That both works with spot and leverage trading settings.