s_ecid vs amcv cookies

[Singaiah_Chintalapudi]

I am trying to find the difference and relation between these two cookies. Can you someone provide more details?

[Anil_Umachigi]

In short 

s_ecid = Contains a copy of the Experience Cloud ID (ECID) or MID.

amcv = The Experience Platform ID Service uses JavaScript to store a unique visitor ID in an AMCV_###@AdobeOrg cookie on the domain of the current website, where ### represents a random string of characters

Read in details about AMCV here and other cookies including s_ecid here

[Singaiah_Chintalapudi]

Thanks Anil. We use WebSDK and I don't see the s_ecid is being consistently dropped in the browsers. So we had to fall back on AMCV.