'Hec est finalis Concordia'
Feet of fines are - technically - court copies of agreements following disputes over real property. However, in many instances the "disputes" were legal fictions: for generations, this was simply a vehicle to get the final agreement (concord) of transfer of ownership of land from Deforciant (def. seller)to Querent (q or quer. purchaser) officially recorded.
They are mostly in Latin until 1733, except for a short period between 1650 and 1660 where English was used.
Since the Victorian times, they have been the subject of calendars and transcriptions by antiquarians and historians. Major publishers have been the Pipe Roll Society and various local Record Societies. The print volumes are quite often to be found in History reading rooms as much as Law. However, many have since been digitised - try for example British History Online via link below.
Subject search in SOLO using Fines and recoveries -- Great Britain
Find digital versions of the earliest treatises on English law to be printed eg Old Tenures, Littleton's New Tenures in EEBO see link below.
Introduction to English Legal History by 
Medieval English Conveyances by 
The Fee Tail and Common Recovery in Medieval England, 1176-1502 by 
Lawyers and the making of English land law, 1832-1940 by From time immemorial, English land had been cultivated using what is known as the open field system. Within these fields the land was further subdivided into strips. Having, renting, or working a farm did not mean that all "your" strips were contiguous.
Laxton (Nottinghamshire) is the famous surviving example of this old system in operation. One of the Treasures of the Bodleian is the Laxton Map - along with the manuscript terrier describing land tenure in the villages of Laxton and Kneesall, Nottinghamshire - both of 1635
Inclosure meant bringing these strips together & from 1604 onwards inclosure was increasingly achieved by private or local act of parliament. (Radipole (Dorset) in 1604 seems to have be the first area so inclosed.)
By the 1750s inclosure by act of parliament was the accepted norm. By 1914 over 5,200 inclosure acts had been passed, affecting over a fifth of the area of England.
Subject searches to find commentary in SOLO:
Inclosures -- History
Land tenure -- England -- History
Commons -- England -- History
The Open Field System and Beyond by 
The Open Fields of England by