Deduction under section 24 is related to the income from house property.

There are a total of 4 deductions from house property, No.1 and 2 pertain to section 24

1. Standard Deduction, which is 30% of the Net Annual Value. This is provided for the annual maintenance of the house property.
2. Interest on housing loan, which is allowed up to the interest payment of Rs 2 lakhs per year.
3. Deduction u/s 80EE. This allowed in addition to the interest on housing loan, for up to Rs 50000. However, this deduction is only available for the first house property for an individual.
4. Pre-construction Interest. This is the total interest you paid during the construction of the property. You can claim the entire interest of pre-construction in 5 equal installments