Every point on a budget line represents one specific combination (bundle) of two goods that uses up the consumer’s entire income at given prices. In other words, each point shows:

  • A particular quantity of Good X and Good Y.
  • A bundle that is affordable and exactly exhausts the budget (total spending = income).
  • A highest-attainable consumption combination for that income level and those prices; anything above the line is unaffordable, anything below leaves some income unspent.

So when you move from one point to another along the budget line, you’re just seeing different affordable bundles of the two goods where the consumer spends all their money.