It may be the newest chess engine, or program.
Questions about "Cloud"

Chessbase "Cloud" is a massive storage of opening tehory analysis specially opening novelties by chess engines. Chess engine users contribute their analysis to the cloud and cloud users can view the analysis instead of repeating the analysis, saving time and effort. It's just like a Wikipedia of opening theory. One can add a new analysis or edit an old analysis with a better one.

"Cloud computing" is fancy marketing jargon for doing something that you would traditionally do on your own computer on someone's server instead. For instance, after each game you play on lichess.org, you can click a button and have queue an analysis of the game. It's "cloud" because you're letting them do all the work. Chess.com also allows you to run engine analyses of your games, but are much stricter about how many you can do.
I just realized you never mentioned any engines. Any chess board in a browser would be considered "cloud" I suppose.

The chessbase "engine cloud" permits you to rent engines/computers located in different places.
If somebody has a very powerful computer, they can also put it there for somebody to rent.
They can also be refering to the "Let´s check" option in chessbase that allows you to check previously analyzed positions by different engines, and that is what Mandy711 was explaining.
The Rybka cluster also allows you to use it remotely, so it could be also "in the cloud" (in some sense):
A Rybka Cluster 100 consists of 100 physical cores and can be rented for 595 Euro (incl. VAT) per day, or 500 Euro (without VAT) per day for customers outside the EU or businesses outside Germany. The minimum continuous Rybka Cluster 100 rental time is 2 days.
http://cluster.rybkachess.com/rent.html
I keep hearing about how some players use "cloud" to examine chess positions.
Someone please explain what is "cloud" and how it works?
Thank you.