What is the difference between shut down point and breakeven point?
At the break-even point the price is just equal to the minimum of SAC and the firm earns normal profit. In such a situation the firm continues production but the revenue earned is just equal to meet its fixed and variable costs.
On the other hand, at the shut-down point the price is just equal to the minimum of SAVC. This suggests that the firm is able to cover the variable cost but not any part of the fixed cost. In such a situation the firm incurs maximum losses. If the price falls any further the firm will not be able to cover even the variable costs and will stop production.