The short answer
An identity graph is a database that links scattered signals, like IP addresses, devices, cookies, and business records, into a single view of who someone is. Visitor identification tools use identity graphs to match an anonymous visit to a company or person. The bigger and cleaner the graph, the more of your traffic a tool can recognise.
Why one signal is not enough
On its own, one signal, like an IP address, only gets you so far. An identity graph connects many signals, so when one is missing or unclear, another can fill the gap. That is why graph quality drives match rate.
It is also why multi-source tools tend to identify more. They draw on more than one graph, so where one is blind, another often sees.
The honest catch: no identity graph is complete or perfectly current. A bigger graph helps, but it is still a probability game, not a guarantee that every visitor is known.
Frequently asked questions
What is an identity graph?
A database that links signals like IPs, devices, and business records into one view of a company or person.
How does visitor identification use it?
It matches an anonymous visit against the graph to find the company or person behind it.
Why does graph quality matter?
Because a bigger, cleaner graph recognises more of your traffic, which raises your match rate.
Querying several identity graphs at once recognises more of your traffic. See how.