1. Different application scenarios: Subcontracting is mainly applicable to partial contracting in general contracting, that is, the general contracting unit contracts some projects to contractors with corresponding qualifications. Blocking is mainly suitable for dividing an overall project into several work objectives with the same nature, and each block can be purchased independently.
2. The contractual relationship is different: in subcontracting, the general contractor does not quit the contractual relationship, but still maintains joint liability with the third-party contractor. In sub-blocks, each block can be undertaken by different suppliers or contractors, and their responsibilities are relatively independent.
3. Different procurement standards: subcontracting is to divide a procurement project under a budget item into several project packages, which can be subcontracted to the same procurement object or to different procurement objects. Bidding is to divide an overall project according to the same nature or work objectives, and the procurement standards of each bid section are basically the same.