In symbols, there are both sensory substances and spiritual meanings, which are unified and inseparable. The connection between this symbol and the reflected object is realized through meaning. Symbols are always meaningful symbols, and meaning is always expressed in a certain symbolic form. The construction function of symbols is to establish a connection between perceptual symbols and their meanings, and present this connection in our consciousness.

Cassirer, a symbolic aesthetician, thinks that "art can be defined as a symbolic language", which is the formal symbolic language of our thoughts and feelings. Every artistic image can be said to be a symbol or symbol system with a specific meaning. In order to understand artistic works, we must understand artistic images; To understand the artistic image, we must understand that, in Cahill's view, symbols, as the reference form of objects, have the functions of generating human nature and shaping human culture.

In the cognitive system, a symbol refers to an image with a certain meaning, which can be a combination of graphics, images and words, or a sound signal, architectural modeling, or even an ideological culture and a current event figure. For example, "=" is an equivalent symbol in mathematics, and "Forbidden City" is a symbol of ancient imperial power in China in politics.

Generally speaking, a symbol means a "special memorial", just like a nickname is a name, which is convenient for people to remember and identify. You should remember that Zhang Lisan may be troublesome, but it is much more convenient with small glasses, so symbols can also be said to be caused by people's cognitive habits.