Hoople - 9:52 pm on Feb 15, 2013 (gmt 0)
Sound like a clustering technology re-spun into new marketing speak ( 'cloud hosting' ).
In conventional hosting your domain, lets call it example.com has a single A record in DNS corresponding to one server IP address.
If the cloud virtualises your site across multiple servers this creates a need for multiple A records, each to an IP address (only one server active at a time). So 'the cloud' would needs to interact with your domain's DNS records.
Done on the cheap a second A record for example.com gets added for each additional data center server IP address. Then DNS would round robin shuffle thru A records to find the live server. This has a time lag performance hit (compared to 'virtualises' above).
Also if multiple servers are involved the who of keeping them in synch and the auditing of the success of same becomes an issue. Time lag of normal synching affect the currentness of what the user sees too.