Most of the time people talk about orphaned blocks, they are actually talking about stale blocks, and have their terminology confused.
Strictly speaking, an orphaned block is a block without a parent. Orphaned blocks used to be seen by nodes which did not yet have the block in question's full ancestry, and so were unable to validate it. This pretty much no longer happens since a change in Bitcoin Core meaning that block headers are synced first before blocks are.
However, because true orphaned blocks don't happen any longer, most people using the term orphaned block actually mean a stale block. A stale block is a block whose parents are known, and which was successfully mined, but was later discarded in favor of another block which was mined at the same height. Occasionally, one miner will produce a block, and while this block is propagating through the network, a different miner will produce the same block. There are now two blocks competing for the same height. When the next block is mined, the block that is not contained with the new longer blockchain will be rejected. This is called a stale block.
You can see a list of stale blocks here:
https://www.blockchain.com/btc/orphaned-blocks