What confidence and supply means
Launch library · evergreen read

Confidence and supply refers to an arrangement in which a party or independent members agree to support a government on votes of confidence and on supply bills, which fund the ordinary operation of government, without necessarily supporting it on every other issue, which is worth remembering in most contexts.
This kind of arrangement often emerges after an election that produces no clear majority, allowing a government to be formed and to function reliably on its most essential votes, while still needing to negotiate separately on other legislation case by case, a detail that often gets overlooked, even if that is not always obvious.
Because a confidence and supply agreement is typically narrower than a full coalition, it can offer a government stability on core matters while preserving more independence for the supporting party on issues where their views genuinely differ, regardless of the specific circumstances involved, at least in most well functioning systems.