What is the difference between volatile variables and atomic variables?

First ,volatile Variables and atomic Variables look very similar , But the function is different .

Volatile Variables ensure antecedent relationships , That is, the write operation will occur before the subsequent read operation , But it doesn't guarantee atomicity . For example

volatile modification count Variable so count++ Operations are not atomic .

and AtomicInteger Class provides the atomic Method can make this operation atomic, such as getAndIncrement() The method will be atomic

Increment the current value by one , Similar operations can be performed on other data types and reference variables .