Mathematical Bold Capital S 𝐒

Visual Description: The character is a bold uppercase S with thick, even strokes. It reads as a strong, compact symbol rather than a word. In math fonts it remains a single glyph, clear and legible at small sizes. When used with other bold letters, it marks a variable or a designated set in equations.

Meaning & Usage: S commonly stands for a set, a space of outcomes, or a parameter in formulas. It can also denote a vector or a scalar, depending on context. In comparisons, S helps distinguish abstract collections from concrete numbers. In user interfaces, bold symbols pair with quick controls for notation and active-variable highlighting.

Historical Background: Bold math symbols grew with modern typesetting to distinguish vectors and special sets. They became common in textbooks and software that render math clearly. The idea is to separate emphasis and roles in an equation without changing its meaning. Over time, fonts and encodings expanded the availability of bold algebraic characters.

Practical Use: In calculations, you may see S used in formulas like S = {elements} or s ∈ S. Calculators and math editors offer quick UI controls for applying operators, summations, or comparisons between S and another set. You can toggle bold styling, switch notations, or adjust parameters to inspect results.

See our category page for related symbols.

Look‑alikes: S (U+53).

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