Differences between NF and $ NF in LINUX-awk commands

LINUX-awk command NF and $ NF differences LINUX-awk command NF and $ NF difference Q & A: 1. What does $ NF in awk mean? # Pwd/usr/local/etc ~ # Echo $ PWD | awk-F/'{print $ NF}' etc NF indicates the number of browsing records. $ NF indicates the last Field (Column). 2. what is the difference between the NF variable and the $ NF variable in awk? {Print NF} also has {print $ NF}. The former outputs the number of fields, and the latter outputs the content of the last field, for example :~ # Echo $ PWD | awk-F/'{print $ NF }'