Are D-latches and D-type flipflops volatile?
Normal flip-flops are volatile, in that they don't remember their state when power is lost.  Usually CPU registers are made from such flip-flops, which is why you need to save stuff you want to remember accross a powerdown to special memory for that purpose.  Since non-volatile is a important attribute, this will be clearly mentioned in any datasheet for a non-volatile memory.  If it doesn't say it's non-volatile, then it's volatile (data lost on power down).

Nowadays, most non-volatile memories are EEPROM (Electrically Erasable Programmable Read-Only Memory).  Flash is a type of EEPROM that you often hear about.  It has tradeoffs that make it cheap for large memories, usually at the expense of write speed and total number of lifetime writes before it wears out.