The gizmo is a tool for fine-tuning the placement of assets while in Edit mode.
You can also reposition a selected asset by grabbing it in an area outside of the gizmo. However, sometimes the gizmo can get in the way, making it difficult to grab the asset without accidentally grabbing the gizmo.
To resolve this, you can turn the gizmo off in the Selected Object menu under the global toggles tab. (near where you Delete or Duplicate an asset).