What is the difference between GIVT and SIVT?
GIVT (general invalid traffic) is non-human traffic that can be caught with simple lists and rules, such as known crawlers, data-center IP addresses and self-declared bots. SIVT (sophisticated invalid traffic) is traffic built to look human, such as hijacked devices, residential-proxy bots, spoofed apps and hidden ads, and it needs advanced analytics to detect.
Both categories come from the MRC's MRC IVT guidelines. GIVT filtering is table stakes: the IAB/ABC Spiders & Bots List, known data-center ranges and obviously broken user agents catch most of it, and any accredited measurement vendor must remove it. SIVT is where the real fraud lives. It includes botnet traffic from infected home computers, residential proxy bots, domain spoofing and app spoofing, ad stacking, pixel stuffing and incentivized or manipulated human activity.
The practical difference is effort. GIVT can be filtered in real time with a lookup; SIVT detection relies on behavioral analysis, device fingerprinting, cross-campaign pattern analysis and sometimes honeypot traps. Vendors are accredited separately for each, so when a report says "IVT rate", it is worth asking whether it covers GIVT only or GIVT plus SIVT.