Fortification

To Fortify something means to reinforce it - however a fortification in this case, refers to a fortified building, or position. There was never any set standard on what defined a "castle",  and people have largely made up their own definitions as they went along. The purpose of this article is to establish terminology that can differentiate between different types of fortifications - for my own benefit. This terminology will apply to The Source Lands Setting.

Terminology
A fortification is often a compounded structure ("compound" for short), meaning it has multiple layers, and then typically, each layer features numerous defenses - however, it can be as simple as a single defensive structure.

Fort
Actually just short for "Fortification", this term specifically refers, to any type of fortification that is not a primary residence. This means that is often a military base or otherwise a place of strategic importance, used to run patrols and/or raids out of. Sometimes just a place for travelers or others to overnight and store cargo - typically in dangerous regions.

Redoubt
A fort built primarily from wood and soil (mounds, levies etc.).
 * When used in plural form, it can refer to the outer defenses of a Fort that, while the main fort does not, remain fashioned from wood and soil - such as exterior mounds, levies or palisades.
 * In real-world terminology, a Redoubt is in a network of levies or trenches extending around a fortification - actually, the star-shaped mounds around a Bastion's main buildings were referred to as redoubts

Bastion
A star-shaped fort used in the era of gunpowder. Note that Bastions as a rule of thumb were forts, as castles needed to be defensible with very few men, whereas the Star-Shaped Fort required a very significant amount of men to defend.

Castle
A Castle differs from a Fort by being the primary residence (or at least the symbolic residence, or seat of power etc.) associated with the owner - but a castle must also feature both a keep and a wall, both of stone. It has to be a compound. The outer walls of a castle are referred to as the "Curtain Walls", and has to be close to above 30 feet in height, otherwise the structure does not qualify as a Castle.

Rampart
A castle made of wood, mounds and levies.
 * When used in plural form, it can refer to the outer defenses of a Castle, or Citadel, that, while the main fortification does not, remain fashioned from wood and soil - such as exterior mounds, levies or palisades.
 * In real-world terminology, rampart is very much synonymous with redoubt, but can mean virtually any walls - the word is essentially empty and does not have a singular meaning.

Citadel
A Citadel is a walled settlement. There is no requirement for a Citadel to have a Keep - but most citadels did, and in fact, most of them featured full-blown castles within the Citadel. As cities grew, they would often expand outside of their walls, and as a direct result, it is uncommon to refer to an actual city as a "citadel" - rather, only the walled part is referred to as a Citadel.

Keep
The word "Keep" describes a primary structure in a Fortification - there were different types, but commonly, the Keep was the primary structure, found at the center of the Compound.
 * The ground levels of the Towers of a Keep were often used as impromptu barracks - typically soldiers slept elsewhere, unless times were dire.
 * The Dining Hall was usually found on the ground floor, and it served multiple other purposes - often used as a war-room in dire times, it was the only room in a castle that was well suited for gatherings.
 * The Court Room was typically also found on the ground floor, but in this was not always the case (the depicted castle features the court room above the dining room). Typically, the Court Room was directly connected to a series of offices where officials stood at the ready to draft documents and take various payments, etc.
 * Private Bedrooms were often found on the top floors for the simple reason that heat travels upwards. It was never a problem to stay cool in a castle - they were by default extremely well insulated.
 * Castles normally had basements, and they often contained vaults, treasuries, armories and prison cells. They were also used for common storage.

Palace
A palace is a type of keep, but is referred to as a "Palace" if it is the primary residence of the owner of the given Fortification that the palace is a part of, but usually only if it has suitable splendor. Less tactical than ordinary keeps, palaces were often heavily decorated. This made upkeep harder, it made it more difficult to notice structural weaknesses that appeared over time, it made it easier to climb them (often), and typically did not allow for many practical and strategic defenses.

Manor-House
A Manor-House was a small keep, sometimes featuring its own compound wall - sometimes not, but it was too small to be called a keep or a palace. Typically, such structures overlooked small villages in less exposed regions, where it was unlikely that the village would need a proper castle, or they were the homes of lesser nobility (knights primarily).

Tower-House
A step up from a Manor-House, a Tower-House was essentially a Keep, but with no compound wall - or at least not with a proper one. Tower-Houses were essentially just small castles a lot of the time - with the only real difference being size or significance.

Common Terminology
See a complete list of common features in Castle terminology here.

Bailey

This particular term can be very confusing - so I've decided to leave a brief and simple explanation of what it actually refers to; A Bailey, in our modern understanding, would be the "upper city" or "inner city" - a separately warded off district, often found in front of the castle - necessitating that one moves through this protected district in order to actually get to the castle.
 * Note that a Bailey did not necessarily contain residences, as much as it held a number of buildings that were militarily important (stables, barracks, armory, mustering grounds etc.).
 * Bailey is synonymous with Courtyard in modern castle terminology, but they are actually two different things - the Courtyard is the space immediately around the Keep - a Bailey, in order to actually be a Bailey, must be entirely separate from the Keep, in its own sub-compound.