what does the flexbox do code example

Example 1: css flexbox syntax

Display: flex 
Flex-direction: row | row-reverse | column | column-reverse
align-self: flex-start | flex-end | center | baseline | stretch
justify-content: start |  center | space-between | space-around | space-evenly

Example 2: flexbox

Please read flexbox & grid in CSS TRIX, 
make hands-on project watching (WESBOS videos - it's really useful)
also try [FLEXBOX - froggy] and [GRID - garden] games