Jujutsu (柔術) as we consider it is a strategy of total body fighting, using everything at your disposal to overcome your enemy, including strikes, joint manipulation, throws, chokes, strangles and even weapons, but without the need to pit strength against strength, or force against force...
This is done using natural body mechanics and principles of movement, which when manipulated correctly can render an attack useless and allow the practitioner to overcome and unbalance their opponent.
There are lots of interpretations of the word Jujutsu: Gentle Art, Supple Art, Art of Yielding, etc, however the translation that we find suits our practice is Soft Skill. Ju 柔 is the Softness that stops us clashing with an opponent, and 術 Jutsu is the Skill and Technique that allows us to use this to our advantage, breaking their structure and overcoming them. This is a very simplified description for the purpose of getting across the basic idea, but the concept goes far deeper than can be explained here.
Mindset is of equal, if not more importance, as it is this that will often dictate your success or failure, regardless of physical prowess or technical ability.
Jujutsu is often referred to as 'Unarmed Fighting of the Samurai' however we do not use this description. Samurai were virtually always armed, therefore Jujutsu had to be able to deal with the threats associated with this, while also allowing the practitioner to execute techniques while wearing weapons themselves, or even enable them to use their own weapons.
This may seem a trivial point, but it is of great importance when you consider the mindset mentioned above, rather than just thinking of a modern brawl or a boxing match, as most do when they think of fighting, when weapons are involved everything becomes a life or death situation.