Karate quite simply,  is a method of fighting involving blocks,  throws,  joint manipulations,  and strikes and can be divided in three parts:  kihon (basic), kata (forms), and kumite (sparring).

The philosophy of karate is that mind and body should become one.  It's like a circle of intention.  To make the physical techniques expressions of our mind's intention while improving the mind's focus by understanding the essence of the physical techniques.  Through this growth we learn to make decisive movements and are able to eliminate weakness.

Shotokan Karate founder Gichin Funakoshi maintains that by being meticulous in the practice of karate we are actually fine-tuning our own spirits (mentally and physically). 

What is Judo?

Judo was developed by Dr Jigaro Kano who was a Japanese educator and martial artist.  Due to the fact that Dr Kano was an educator, it made perfect sense that when he modified Jujitsu to create Judo, he had in mind to make it accessible for children as well. Judo was developed during the Meiji period when Jujitsu schools were in danger of closing during the rush to westernize the country.

Judo is a form of hand-to-hand combat used when weapons are lost leaving only the hands to defend oneself. It is a "gentler" form of Jujitsu, therefore good for children and at the time was more acceptable to the western influences that were penetrating Japanese culture at the time.

 Dr Kano wanted to achieve two things when he was working on the development of Judo.  He wanted Judo to be practiced without hurting the opponent.  It was difficult to practice Jujitsu due to the very real danger of harming your opponent.  He also wanted to work with strength in a maximally efficient way, so that even a small student would be able to topple someone much larger than him/herself.