While some languages rely on on a consistent statement terminator, others provide a distinct statement separator for situations in which multiple statements are written in an area where only one may otherwise be expected.
Typically these are languages which are typically line-oriented and therefore a line break is the typical statement terminator, but the separator allows for multiple statements on the same line.
The distinction may get fuzzy in some cases such as JavaScript where the automatic semicolon insertion enables terminators that may be considered optional, but the distinction made here is that separators are not consistently appropriate or expected, but are introduced for the reason described - to effectively squeeze multiple statements in the place of one.
This is an informal concept based on convention, there is not for example a hard expectation or grammar production that a separator must be followed by another statement but that would typically be the case based on idiomatic language usage and separators would not otherwise be used.
; is available as a statement separator and can also be
used as means to enable that would not otherwise be valid. In typical
use ; would be omitted, likely largely due to Bash’s role
as a shell.