A Position indicates the number of Assets you own on a specific Account. If you buy more of the same asset on the same account, your position increases. Conversely, if you sell some of that asset, the position decreases.
Multiple Positions for a Single Asset
It's completely fine to have multiple positions for a single asset. This can happen if you own the same asset across different accounts. Each account will have its own position for that asset. So, a single asset can have as many positions as the number of accounts you have.
Deleting one position without deleting the asset
Delete position, in the ⋮ menu on a position row, removes that asset's transactions in that one account and leaves your other accounts untouched. Delete asset takes every transaction of the asset with it, in every account, and asks you to confirm when the asset is held in more than one. A row with no transactions of its own has nothing to delete, so only Delete asset is offered there.