control characters in import csv file

Hello,

In the "import csv file" window there are "fields terminated by" "fields enclosed by" and "fields escaped by" under control characters, what is the difference between them ? I mean i can understand "fields terminated by" and i changed it from " to , in order to import a csv file, but what about "fields enclosed by" and "fields escaped by" ? also what is "optionally" means ? I had a csv file with empty fields and when i uncheck this box all fields imported correctly but i want to know what these things means.

thank you

https://dev.mysql.com/doc/refman/8.0/en/load-data.html#load-data-field-line-handling