There was a famous Chinese traditional poem which described how to play this traditional musical instrument Pipa (琵琶).
“轻拢慢捻抹复挑” (qīng lǒng màn niǎn mò fù tiǎo)
拢、抹、捻、挑 are four different playing ways. They indicate how your fingers play.
There are various translations to help you understand :