According to dictionary.com, 'renovatus' originated in the early to mid 1400's, which is latin for the Middle English term 'renovate' meaning to restore to good condition. 'Remodel' was first recorded in the 1780-90's which means to reconstruct or make over.
Both terms are used interchangeably, but it is important to note the distinction when starting a project on your home. As mentioned, renovate indicates that you would like to keep and restore certain aspects of an area, whereas remodeling indicates that you would like to remove everything and redo the entire area.
To avoid confusion of the terms, these are sometimes referred to as a partial and full remodeling projects. These are the preferred terms in the construction industry because it gives a clear picture to the contractor of whether everything is going or some of it.