question on understanding DirectQuery and live connection

i am pretty new to power BI.
i thought the DirectQuery queried the database and brought into itself a cache of the data. and then you can set a refresh schedule for when it should reload that data.
but when i did this there was no increase in size of my pbix file NOR an increase in my storage limits in power BI workspace online.

so does DirectQuery query the database live when someone hits a chart?
does DirectQuery = live connect?