A COBOL compilation group may contain one or more compilation units.
Apart from the source text manipulation statements and END markers, all statements, entries, paragraphs and sections of a COBOL compilation unit are grouped into four divisions, which are organized as follows:
Identification Division
Environment Division
Data Division
Procedure Division
The end of a COBOL compilation unit is indicated either by the END marker or by the absence of further compilation unit lines.
The beginning of a division is indicated by the corresponding program division header or the corresponding ID or FACTORY or OBJECT. The end of a division is indicated by
the division header or ID or FACTORY or OBJECT of a succeeding division in the program or
an END marker or
the absence of further source lines.
Although a COBOL program may have an unlimited number of lines, the compiler will only number these lines uniquely up to a value of 65536.