True. Also, wink almost always involves closing only one eye, usually on purpose as a kind of 'signal' to someone. Blink is generally when you close both eyes very quickly, like you do naturally every few seconds without thinking about it.
Winking is the act of closing and reopening one eye. People do it to flirt or to signal that they're lying or for other social purposes like that.
Blinking is the act of closing and reopening both eyes. People do it either voluntarily or involuntarily when there is something caught in their eyes. You can also "blink back" tears (blink rapidly so that it's not obvious that you're about to cry). Since it's usually involuntary, blinking doesn't have any particular connotations.