Answers for "what is flexbox box and usage"

flexbox

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

flexbox elements

Flexbox Notes

- display: flex; (the container)
-flex-direction: row | row-reverse | column | column-reverse;
-flex-wrap: wrap;/no-wrap
-justify-content: start |  center | space-between | space-around | space-evenly
-align-items: flex-start | flex-end | center | baseline | stretch | inherit | initial
-height: xx;
-width: xx;
-flex basis: auto-'default value'| number | inherit | initial;
-flex-basis- 20em (used to control size)
   flex: 1(grow) 2(stretch) 20em (starts with{initial size}-basis)