What is oblivious RAM and how does it work?

Could anybody explain me what exactly oblivious RAM is?

I found the following explanation which makes it kind of clear to me, but I would like to get a sense of the technical aspects:

Encryption is not always enough to ensure privacy. If an adversary can observe your access patterns to encrypted storage, they can still learn sensitive information about what your applications are doing. Oblivious RAM solves this problem by continuously shuffling memory as it is being accessed; thereby completely hiding what data is being accessed or even when it was previously accessed.