Nodes check the rules
A full node downloads and validates blocks and transactions according to the consensus rules it implements. It can reject data that fails those checks, even if a miner produced it.
Miners propose blocks using proof of work
Mining software builds a candidate block and mining hardware searches for a block-header hash below the current target. A successful result lets the miner propose that block to the network; it does not force other nodes to accept an invalid block.
Worked example: an invalid block
Imagine a miner finds valid proof of work but includes a transaction that violates a consensus rule. A validating node checks the block’s contents and rejects it if it is invalid. Proof of work demonstrates work on a candidate; it does not replace rule checking.
The roles can run together
Mining operations commonly use node software to obtain transaction and block data and to submit completed blocks. That does not make “node” and “miner” the same job: one describes validation and network participation, while the other describes block construction and proof of work.
Why the distinction matters
A node operator can verify the chain without mining. Mining does not give a participant permission to change rules for other nodes. Consider what verification or mining goal you have before choosing software or hardware.