Four basic types of plasticity of the brain work are distinguished: compensatory, developmental, hemispheric, and competence plasticity. It is also stressed that all those changes are of a functional character due to the reorganization of interneuronal connections within the whole brain. The plasticity, however, is mainly a feature characteristic of our mind, which works in an indeterminate, open way. The open nature of the mind is due to a manner of information processing within the brain since a specific diffusion of outer sensations with inner knowledge takes place there. It is reflected in a human language which violates rules of the formal logic. Consequently, the brain and the computer do work in an entirely different way.