IIRC is means a pictorial definition of a value so the above is a float printable using 12 positions which for maximum value would be as 999999999.99 While a PIC X(10) Means character string length 10. It was defined in era of fixed width fonts and band printers so the max printing width was 132 and one had to know exactly where each character would print. Report writing in COBOL is easy.

PIC is short for PICTURE, which was the original form of the keyword. Picture the number printed this way.

Edit: the numbers in parentheses are repeats. PIC 9(9) means up to 9 digits in the printed representation of the value stored in the variable that has this PIC.