A general term used to refer to the consolidation of 
companies. A merger is a combination of two companies to 
form a new company, while an acquisition is the purchase of 
one company by another with no new company being formed.

Corporation that owns enough voting stock in another 
corporation to influence its board of directors and 
therefore to control its policies and management. A holding 
company need not own a majority of the shares of its 
subsidiaries or be engaged in similar activities. However, 
to gain the benefits of tax consolidation, which include 
tax-free dividends to the parent and the ability to share 
operating losses, the holding company must own 80% or more 
of the subsidiary's voting stock.

actually merger means merging of two companies to form a 
new company is called merger

acquisition  - big comanies acquiring small company is 
called acquisition shortly known as obserption

holding company- holding company is the main company which 
hold 51%of shares