Unlike 每měi ‘every’, 各 gè ‘each’ only occurs with particular types of nouns, such as communities, countries, institutions, categories, etc. which may also be taken as collective measures.
Unlike 每měi, which emphasizes totality, 各 gè emphasizes individuality and may be used as a pronoun in some reduplicated structures:
gè gù gè
each for oneself
gè yǒu gè de tè diǎn
Each has its own characteristics.
Gè yǒu gè de xiǎng fǎ
Each has his/her own axe to grind.
Gè jiù gè wèi，yù bèi，qǐ ！
On your marks; get set; go!
 Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.