How is this material collected and stored?
Items deposited under Electronic Legal Deposit (eLD) are collected from publishers or self-submitted via an online portal and then processed at the British Library. The digital objects themselves (e.g. PDFs for journal articles, ebooks in epub format etc) are stored on specially-commissioned servers at the British Library datacentres in London and Yorkshire and replicated to similar nodes at the National Libraries of Scotland and Wales.
Metadata (i.e. catalogue records) for the ingested items is then made available to the Legal Deposit Libraries to be incorporated and indexed in their local discovery services. At Oxford new records for eLD items are added to SOLO on a daily basis by a scheduled process which checks the British Library servers for new metadata and processes the records accordingly.
When an eLD item in SOLO is viewed it is via the British Library's secure delivery mechanism which ensures that access and use complies with the relevant legislative requirements.