The dictionary meaning of modify as a noun is making or becoming various, difference to previous state, replacement of one for another variation, etc. Change as a verb means to undergo change, to make or become variant. Change fundamentally denotes dissatisfaction with the old and urge for the new. It might be perceived in two ways:
1 Change as continuous and intrinsic to an organisation: There are changes within an organisation which are minute in nature but take place continuously. An organisation might be perceived as being in a state of flux (like the universe) and the elements of its systems and sub-systems always undergo subtle changes (incremental changes).
2 Change as extrinsic and discontinuous: Organisations are perceived as generally stable and change is perceived as disruptive and forcing organisations to change, restructure or reconfigure. Many changes occurring inside the organisation are extremely minute and their impact is hardly felt. But a few modifications are cataclysmic in nature, providing the organisation barely any time to cope along with them. These are almost like natural calamities like as cyclone, earthquake, etc. in their impact. A few organisations might handle changes within a creative manner or make drastic changes in their strategy and direction to emerge out of this turbulence whereas others might get lost in it.