The 2nd house covers personal resources in the most literal sense, income, possessions, and the material security someone builds for themselves, but also the less literal sense of self-worth: what you believe you're actually worth, separate from what anyone else says.
It's a succedent house, describing what gets built from the 1st house's initial self-presentation, and sits opposite the 8th house, where resources stop being purely personal and start being shared, merged, or inherited.
The 2nd house traditionally rules movable possessions and personal income, the money a person earns directly and the belongings they acquire through their own effort, as distinct from the 8th house's shared or inherited resources. It also governs personal values in a very practical sense: what someone considers worth paying for, saving, or holding onto, and by extension their sense of self-worth, since what a person believes they deserve to have tends to move in step with what they believe they're actually worth.
That link between money and self-worth isn't incidental. Long before a person can describe their own value in the abstract, they learn it through concrete evidence: what they're able to earn and keep, whether effort reliably produces something durable. Built from the 1st house's initial self-presentation and opposite the 8th house of merged resources, the 2nd house marks the boundary of what's fully a person's own to manage, a boundary they're sometimes asked to loosen once the 8th house's demand for shared or surrendered resources enters the picture.