"People from the ads" counts visitors who arrived from a Meta ad, excluding your own test visits, bots, and Meta's ad-review servers (they open every ad from data centres like Prineville, Forest City and Clonee and leave after about 30 seconds). "Stayed 30s+" means the page was open and active for at least 30 seconds. "Other traffic" is visits without an ad tag, almost all scanners and link previews. Ad spend isn't included; it lives in Meta Ads Manager. Refreshes every minute.