What does feature mean in QGIS?

Notwithstanding whether there are non-geographical features, I think of a feature as being something with geometry (x,y etc) and attributes i.e. a feature is more than geometry. Then when a feature (as part of a feature class) is displayed on a map it also has symbology (points drawn in red dots of 10pts, etc) and can be referred to as part of a layer.

In other words, glossing over many details:

• feature = geometry + attributes
• feature class = collection of features
• layer = feature class + symbology