I would like to know why memory structures in Oracle such as the buffer cache, redo log buffer, etc. are called structures, rather than memory areas? Are there are smaller components they are composed of? If they are nothing but chunks of memory, why do we call them structures? I think it still makes sense to talk of physical structures, such as files since they are collections of disk blocks. But I would really appreciate if you explained why we refer to memory structures as such. Thanks.