Digitised records - what exactly are these?

I read a report in the Irish Times this morning of a plan to digitise Observatory recordings of Irish speakers way back then etc. Link here: [broken link removed]

While I understand how one would digitise recordings etc I was wondering when they digitise documents - what does this mean? Is it merely taking a (fancy) digital pic of a document and cataloging it or does it go further and allow one to search the document. For example could one, in the case of genealogical records, search for the hansov clan in the past? Or would one need more specific information such as location and date and then have to search a digital pic?

You can OCR (read the characters) scan documents which are then searchable. This will not work for handwritten records.

So in the case of say, records of births etc, digitising these would basically be digital pix as OCR won't work.

things have moved on since this http://answers.google.com/answers/threadview/id/484756.html
but I've yet to see a good working large scale joined writing to text scanner. If something is catalogued correctly the image scan should be adequate for searching - in this case you would search based on database fields that the archiving software would create based on the document.