The term "contract" is used in this book to cover the great variety of forms of agreement which are given to purchasers, or prospective purchasers, of real estate, and which are known as leases, conditional contracts of sale, bonds for title, agreements, contracts, etc. In this chapter the words "contract," "agreement," and "lease" are all used to describe an agreement providing for sale on the instalment plan.

Perhaps the simplest form of such agreement is one which gives the prospective purchaser the right to occupy certain described lands for a specified time, and also the right to buy those lands during that time at a specified price, provided he makes the required payments. These payments may consist merely of interest at the current rate on the amount of the purchase price, the vendor agreeing that, if all conditions are complied with (including the payment of the purchasing price), he will, at any time during the life of the lease, deliver a deed to the purchaser, conveying good title.

There are many varieties of contracts more elaborate than this, but all of them observe the principle that, upon the conditions specified being carried out by the purchaser, the vendor will convey title to him. The periodic payments may vary to any extent, the usual minimum, as in the case above mentioned, being merely interest on the principal.