Start with what a contract buys. The FAR defines acquisition as the acquiring by contract with appropriated funds of supplies or services (including construction) by and for the use of the Federal Government through purchase or lease 1.
For research, the FAR draws the line by purpose. Contracts shall be used only when the principal purpose is the acquisition of supplies or services for the direct benefit or use of the Federal Government 2. Grants or cooperative agreements should be used when the principal purpose of the transaction is to stimulate or support research and development for another public purpose 3.
Worked example. A two-person lab builds a sensor a civilian agency might use. It keeps two lists: grant notices for research funding, and contract notices where an agency wants to buy sensors for its own use. Each list gets its own go / no-go questions.
Where grant opportunities are listed
Federal grant notices have their own home. Grants.gov states its mission as to provide a common website for federal agencies to post discretionary funding opportunities and for grantees to find and apply to them 4.
Bids2Bank's Find Grants page searches Grants.gov's public search API live on every search and stores nothing 5. Its filters separate opportunities that are open now from those labelled "Coming soon (forecasted)" 6.
Small businesses doing research should also know the SBIR and STTR programs: through them, SBIR.gov says, America's Seed Fund awards non-dilutive funding to develop your technology and chart a path toward commercialization 7.
Indented paragraphs are invented worked examples. Tool links open Bids2Bank and need a free account.