What does writing in such signs % % mean?

Question

symfony

What does writing in such signs % % mean?

driver: pdo_mysql
        host: '%database_host%'
        port: '%database_port%'
        dbname: '%database_name%'
        user: '%database_user%'
        password: '%database_password%'
        charset: UTF8

Answer 1

Doesn't mean anything, instead of %something% you need to insert your connection data so that it looks like
host: 'localhost'