law: Transfer of Property Act, 1882
  58. "Mortgage", "mortgagor",
  
  "mortgagee", "mortgage-money" and "mortgaged"
  
  defined.
  (a) A mortgage is the transfer of an interest in specific
  
  immoveable property for the purpose of securing the payment of money advanced
  
  or to be advanced by way of loan, an existing or future debt, or the
  
  performance of an engagement which may give rise to a pecuniary liability.
  The transferor is called a mortgagor, the transferee a
  
  mortgagee; the principal money and interest of which payment is secured for the
  
  time being are called the mortgage-money, and the instrument (if any) by which
  
  the transfer is effected is called a mortgage-deed.
  (b) Simple mortgage- Where, without delivering possession
  
  of the mortgaged property, the mortgagor binds himself personally to pay the
  
  mortgage-money, and agrees, expressly or impliedly, that, in the event of his
  
  failing to pay according to his contract, the mortgagee shall have a right to
  
  cause the mortgaged property to be sold and the proceeds of sale to be applied,
  
  so far as may be necessary, in payment of the mortgage-money, the transaction
  
  is called a simple mortgage and the mortgagee a simple mortgagee.
  (c)  Mortgage by conditional sale -Where, the mortgagor
  
  ostensibly sells the mortgaged property-
  on condition that on default of payment of the mortgage-money on
  
  a certain date the sale shall become absolute, or
  on condition that on such payment being made the sale shall
  
  become void, or
  on condition that on such payment being made the buyer shall transfer
  
  the property to the seller,
  the transaction is called a mortgage by conditional sale and the
  
  mortgagee a mortgagee by conditional sale:
  PROVIDED that no such transaction shall be deemed to be
  
  a mortgage, unless the condition is embodied in the document which effects or
  
  purports to effect the sale.
  (d) Usufructuary mortgage- Where the mortgagor delivers
  
  possession or expressly or by implication binds himself to deliver possession
  
  of the mortgaged property to the mortgagee, and authorizes him to retain such
  
  possession until payment of the mortgage-money, and to receive the rents and
  
  profits accruing from the property or any part of such rents and profits and to
  
  appropriate the same in lieu of interest or in payment of the mortgage-money,
  
  or partly in lieu of interest or partly in payment of the mortgage-money, the
  
  transaction is called a usufructuary mortgage and the mortgagee a usufructuary
  
  mortgagee.
  (e) English mortgage- Where the mortgagor binds himself to
  
  repay the mortgage-money on a certain date, and transfers the mortgaged
  
  property absolutely to the mortgagee, but subject to a proviso that he will
  
  re-transfer it to the mortgagor upon payment of the mortgage-money as agreed,
  
  the transaction is called an English mortgage.
  (f) Mortgage by deposit of title-deeds- Where a person in
  
  any of the following towns, namely, the towns of Calcutta, Madras, and Bombay,
  
  and in any other town which the State Government concerned may, by notification
  
  in the Official Gazette, specify in this behalf, delivers to a creditor or his
  
  agent documents of title to immovable property, with intent to create a
  
  security thereon, the transaction is called a mortgage by deposit of
  
  title-deeds.
  (g) Anomalous mortgage- A mortgage which is not a simple
  
  mortgage, a mortgage by conditional sale, a usufructuary mortgage, an English
  
  mortgage or a mortgage by deposit of title-deeds within the meaning of this
  
  section is called an anomalous mortgage.