Public procurement is the process by which government bodies and other publicly funded organisations buy goods, services, and works from external suppliers. Because it spends public money, it is governed by rules requiring open advertising, equal treatment of bidders, and transparent award decisions.
The rules differ by country but the principles are remarkably consistent worldwide: requirements must be published rather than negotiated privately, all suppliers must be given the same information, award criteria must be stated in advance and applied as stated, and unsuccessful bidders must be told why they lost. Contracts above certain value levels attract stricter procedures and wider advertising than smaller ones.
For a supplier, this creates a market with unusual properties. Entry is open rather than relationship-gated, the specification and the scoring sheet are handed to you before you write anything, and decisions can be challenged if the process was not followed. The trade-off is process: formal eligibility documents, prescribed formats, and hard deadlines that carry no discretion. Learning that process once is what turns public procurement from a barrier into a durable source of contracted revenue.