Content hierarchy in the docstore can be thought of as a file system with folders and files. Wherever it says "nt:folder" one can - think of it to behave as behaving like a folder that can contain one or more folders and files. Where ever Wherever it says "nt:file" one can think of it as a file with actual content in it. For the MARC content hierarchy represented in the picture on the left, what it means is at L1 there can be 1 or up to 1K folders. Each MARC folder can in turn have one or up to 1K more MARC folders at L2. Each MARC folder at L2 can then have 1 or up to 1K more MARC folders at L3. Each MARC folder at L3 can then have the up to 1K actual MARC files up to 1K. | 
