Land records are very complex. There may be many transactions and documents relating to one parcel of land. Procedures and requirements for acquiring and transferring land -- and for the associated record-keeping -- may have changed over time.
A useful distinction to keep in mind when researching land records is the difference between Crown grants and private land transactions. All land originally belongs to the Crown -- that is, to the government. Crown land may be owned by the provincial or federal government which may grant it to individuals or corporations through means such as purchase, pre-emption, or auction. Once land has been alienated from the Crown and is privately owned, it can be transferred to others through private transaction.
Information on Canadian land records is available on the Library and Archives Canada's Land Records page.
The subject is also explored in Sharon Murphy's book: Researching Canadian Land Records.