The deposit is an amount of money that you pay to the landlord. It ensures that he or she can repair the lease and return it to the state it was in when you moved in. You cannot be sure to get your deposit back. It depends entirely on what is stated in the contract about maintenance and repair costs. According to Danish law, the amount of the deposit may not exceed that of 3 x the rent, not including utilities.
Prepaid rent is rent intended to cover the end of your stay in the property. You pay this in advance, when you move into your new home. When you terminate the lease, you will not have to pay rent in the number of months corresponding to the amount you paid in prepaid rent. For instance, if you have paid three months' rent in advance, you do not have to pay rent the last 3 months you live in the property. This is the landlord’s assurance that you do not move out from one day to the next.
A/C is an estimate of the use of water and heat in the property. The estimate is normally based on previous tenants. The amount may vary depending on your usage. This means that the actual, annual usage may be more or less than the estimate, and you either have to pay extra or maybe getting a refund.
What is included in the A/C varies from landlord to landlord, but it usually includes water and heat. Electricity is typically not included, but paid directly to the electricity company by the tenant.