Though now synonymous with fealty, homage and fealty were once separate parts of a ceremonial commendation of feudal tenure. This ceremony was the formal part of how a feudal tenant and lord relationship was created. Pollock and Maitland, in their great work The History of English Law before Edward I, have a description translated from Bracton:
The tenant puts his hands between the hands of the lord--this symbolical subjection seems from the first to have been the very essence of the transaction--and says: 'I become your man of the tenement that I hold of you, and faith to you will bear of life and member and earthly worship, and faith to you shall bear against all folk who can live and die, saving the faith that I owe to our lord the king.'
Some more details come from other commentators like Littleton and Britton:
Britton adds that the lord shall then kiss his tenant; Littleton adds that the lord sits, while the tenant kneels on both knees, ungirt and with his head uncovered.
Having "done" homage, the vassal then stands to swear the oath of fealty by which he demonstrates his faith; again Pollock translates from Bracton:
The tenant now stands up with his hand on the gospels and says: 'Hear this my lord: I will bear faith to you of life and member, goods, chattels and earthly worship, so help me God and these holy gospels of God'; some add an express promise to do the service due for the tenement.
In this ceremony therefore is found the very essence of the feudal relationship. The holding of land between lord and vassal is tied up with his faith and observance of earthy worship and the services of the tenement. Pollock further notes that the poor scribes of manors who recorded oaths of fealty in Latin ('fidelitas') often misspelled it as 'feodelitas' or 'feoditas', so close was the relationship between faith and the fee of which a vassal held of his lord. The fee in this case is the anglicised 'feodum' and found in the phrase 'fee simple' or 'fee tail'. The feudal relationship is not just a legal construct but also the basis of the society which existed with the king at the apex, binding each rung with oaths of faith and service in return for the benefits of land.