In the simplest form, chunking means breaking complex, long structures into simpler blocks. The closest example is a bank card number: 3456 6578 5220 4534. The same applies to phone numbers — in blocks they are much easier to read.
Where chunking was truly needed — accounting systems. Cash register numbers, invoices, identifiers dozens of digits long. In the era of manual entry in FoxPro, chunking never existed. Try not to lose your place: 8363700000000000000000354.
Electronic document flow partly solved the problem.
But we are talking about aesthetics and design. So when you typeset data, use this.
Important: split numbers with letter spacing rather than spaces (where the system allows), so copying to clipboard does not add extra characters.