Ewelink Web page

Can anyone explain the exact meaning of the icons shown next to devices field needing updates in the web app?
Examples:
a) A white arrow inside a green circle (current version field);
b) The word DST inside a black circle that looks like a clock (latest version field).

a: indicates that the current version is not the latest and can be updated to the latest version.

b: indicates that the latest version supported by this device allows automatic switching between daylight saving time and standard time.