WHAT IS STRING THEORY ??

 String theory -

In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and interact with each other.

Or in SIMPLE WORDS WE CAN SAY

String theory proposes that the fundamental constituents of the universe are one-dimensional “strings” rather than point-like particles. ... String theory also requires six or seven extra dimensions of space, and it contains ways of relating large extra dimensions to small ones.

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