Among other things they are aggregators of all types of personal data like name, current and prior addresses, phone #s, vehicles owned, insurance carried, etc etc which they provide for a fee to all types of entities including the CRAs.
They're considered a source of truth yet often have errors in their data. It's not unheard of to dispute off incorrect data from a CRA then have it repopulated at a later date because the purported source of truth has flawed data.
You're welcome. You will want to request a copy of your full consumer report which they will send to you for free and you can dispute incorrect data.
The amount of info that they manage to collect on you is surreal, the full report can easily be a few hundred pages long.
@IcantThinkofAdecentNAME what's the shipping cart trick?
Some Comenity-issued co-branded cards can be acquired without taking a hard pull. The technique used to be quite reliable but over the last 2 years or so it's become much more YMMV about avoiding the hard pull.
DoC has a pretty good detailed explanation.
An offer pops up while you're checking out telling you that you're preapproved for a certain amount. Mine was a soft pull but there are ones that get hard pulls too.