Left one is “NotEqual Boolean”.
Right one is “And Boolean”.
The red input and output pins indicates that it is a Boolean type. If you start dragging a string from the output pin while “Context sensitive” is checked then your selections in the drop-down will show Boolean versions of “and” “Not Equal” etc.
The first one appears when you drag from a boolean output pin and search for “NotEqual boolean” in the resulting context window. The second one appears when you search for “And boolean” instead.