Anti siphon device? are those supposed to release water when valve being closed?

[roehrich]

I have this device on my faucet in the garage. Is this an anti-siphon? Or vacuum breaker? Is this the same?
Whenever I close the valve after using my hose it will release water. Has been doing this since I moved into the house years ago. Is this by design?

 

[930dreamer]

Yes by design!

 

[Sponsor]

 

[Slomoola]

Frost free feature.

 

[GReynolds929]

Anti siphon feature.