A symbol could be described as something familiar which represents something more vast or abstract (e.g. an idea or concept). The design of the Scout emblem, for example, which is familiar to all of us in Scouting, is symbolic in nature - the reef knot which symbolizes the unity of the Movement, and so on.

Symbols are often used to help communicate concepts which may not be familiar to people through inviting them to think beyond the most apparent meaning of things that are already familiar to them. Symbols communicate through an appeal to the imagination and experience - without the need for advanced powers of reasoning or complex language.
In Scouting, a symbolic framework is a set of elements which represent concepts which Scouting seeks to promote. The very name of our Movement - Scouting  refers to a symbolic framework  invented by its founder, Baden-Powell, and was intended to appeal to boys in late childhood-early adolescence (the only age section - and gender  catered to at the time).

Originally, the name of Scouts came from soldiers in the armed forces who went on reconnaissance trips ahead of the rest in order to determine whether or not it was safe for the others to follow. They survived through their knowledge of nature and general resourcefulness. 

However, it is important to remember that, despite his military background, Baden-Powell sought to promote peace, tolerance and good will:

It is also important to remember that Scouting began in a particular sociopolitical context (Britain, in the early 20th century) in which, as B-P knew, “Scouts” conjured up images of adventure, courage and chivalry, close-knit groups, developed powers of observation, resourcefulness and a simple healthy life in the great outdoors - all qualities which he sought to promote:
As Scouting began to cater to the needs of young people outside of this original age group, the need became apparent to develop other symbolic frameworks for them. The symbolic framework changes, therefore, from one age section to the next so as to correspond to the young people’s level of maturity and to focus on the specific needs of the various age groups.
At the same time, however, “Scouting” has remained the name of our Movement - and “Scout” is the generic term in English for a youth member of any age. Whatever the term used in other languages, the symbolism remains faithful to the original intention (e.g. “Pathfinder”, or a person who “lights the way”). 

In many countries, the symbolic framework of Scouts with their troop and patrols is still used for the late childhood-early adolescent age section. However, whatever the symbolic frameworks used for the various age groups, “Scouting” remains as an overall “umbrella” symbolic framework, thereby creating a link between all members wherever they may be.

In order to cater to the needs of young people at different ages, each age section has a symbolic framework which is expressed as a central theme (inspired by children’s fables, mythology, legendary heroes, a period in history, etc., or which may be totally invented). It involves a way of life which represents the personal qualities and collective way of life which Scouting seeks to promote and focuses on the major educational need in the educational proposal that characterises a given age group. Examples of such needs are: learning to live together for a young age group, adventure and survival for the subsequent age group, exploring new horizons, involvement in community or environmental issues, etc.