What is the difference between structural and displayed formula?Watch
Structural formulas are a class of chemical formula not a single one, but the terms are used quite loosely.
Condensed structural formulas (often just called structural formulas) are the type like: CH3CH2CH2CH3
A full displayed structural formula (often just called displayed formula) is the one that shows all the individual bonds.
The broader term (for all types) is the one used in the definition of a isomer: same molecular formula, different structural formula - to mean either/both of the types mentioned above.