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.
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.