How does string theory differ from the point-particle model used in conventional particle physics?

In conventional particle physics, subatomic particles are modeled as zero-dimensional point particles. In contrast, string theory proposes that these particles are actually tiny, one-dimensional "stringlike" entities.1

While these strings are so small (approximately ${10}^{-33}$ cm) that they appear as points to observers, their internal structure is fundamental to the theory. The primary differences include:2

• Vibrational States: In string theory, a particle’s properties—such as its mass and charge—are determined by the specific vibrational pattern of the string, much like how a violin string produces different musical notes.12
• Unification: String theory aims to provide a unified field theory by incorporating all four of nature’s forces—gravity, electromagnetism, the strong force, and the weak force—into a single quantum mechanical framework, a feat the Standard Model does not achieve.12
• Extra Dimensions: To maintain mathematical consistency, string theory requires the existence of additional spatial dimensions beyond the three of common experience, which are theorized to be "crumpled" or hidden at scales too small to detect.2