Lead Capture Form
A short form, usually just an email field or two, whose only job is collecting a visitor's contact details before they leave your site.
A lead capture form trades brevity for volume: the fewer fields it asks for, the more visitors will finish it. Asking only for an email typically outperforms asking for name, email, and phone number by a wide margin.
Where extra fields do earn their keep is in lead quality: a form that asks "What are you looking for?" alongside the email can route a lead to the right follow-up automatically, at the cost of some completions.
Placement changes what a lead capture form is really for. Embedded in a page, it is a passive option for the already-convinced. As a popup, timed to intent or scroll depth, it is an active ask, and needs a stronger reason to say yes.
See it in practice