Offer / Bid / Proposal

“Offer” means a response to a solicitation that, if accepted,
would bind the offeror to perform the resultant contract.
Responses to invitations for bids (sealed bidding) are offers
called “bids” or “sealed bids”; responses to requests for proposals
(negotiation) are offers called “proposals”; however,
responses to requests for quotations (simplified acquisition)
are “quotations,” not offers. For unsolicited proposals, see
Subpart 15.6.

“Solicitation” means any request to submit offers or quotations
to the Government. Solicitations under sealed bid procedures
are called “invitations for bids.” Solicitations under
negotiated procedures are called “requests for proposals.”
Solicitations under simplified acquisition procedures may
require submission of either a quotation or an offer.

Источник: Federal Acquisition Regulation at https://www.acquisition.gov/far/