A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.

The opacity attribute specifies the transparency of an object or of a group of objects, that is, the degree to which the background behind the element is overlaid.

The cy attribute define the y-axis coordinate of a center point.

Classes are a template for creating objects. They encapsulate data with code to work on that data. Classes in JS are built on prototypes but also have some syntax and semantics that are unique to classes.

The max attribute specifies the maximum value of the active animation duration.

The name attribute specifies either the name of a color profile or a font face.

The let declaration declares re-assignable, block-scoped local variables, optionally initializing each to a value.

The switch statement evaluates an expression, matching the expression's value against a series of case clauses, and executes statements after the first case clause with a matching value, until a break statement is encountered. The default clause of a switch statement will be jumped to if no case matches the expression's value.

The font-size attribute refers to the size of the font from baseline to baseline when multiple lines of text are set solid in a multiline layout environment.

The const declaration declares block-scoped local variables. The value of a constant can't be changed through reassignment using the assignment operator, but if a constant is an object, its properties can be added, updated, or removed.