The [[glyph]] '''dot''' or '''period''' refers to the <code>.</code> character. It represents several unrelated concepts, some derived from traditional mathematical notation. The dot is one of the most [[wikipedia:Operator_overloading|overloaded]] APL symbols:
* In all dialects, it is used as [[wikipedia:decimal_separator|decimal_separator]], for example <source lang=apl inline>3.14</source> representing <math>3+\
* In all dialects, it is a [[dyadic operator]] with function [[operand]]s, deriving a [[dyadic function]] (<source lang=apl inline>X f.g Y</source>) which is the generalised [[Inner Product]]. Specifically, (<source lang=apl inline>X +.× Y</source>) is the [[wikipedia:dot product|dot product]].
* In all dialects (although deprecated in [[SAX]]), dot with a [[Jot]] on on its left, forms the [[Outer Product]] operator.