Is it true that most of the employers recruit their employees by references or introductions by their existing employees ?

it's 80% true but not for all positions, it's true for the med level and upper management positions.

It depends on the employer! My job as a recruiter is to identify talent and maintain relationships with employers to set professionals up for success

The internal reference is a report with no influence on the search and evaluation of the best talent on the market.

The presentation of an employee follows the same assessment process as other candidates.

The value of the reference would be important in relationship with the knowledge and experience of the eomployee

References and employee referals can definitely give a candidate an advantage in the hiring process, assuming the referer and/or employee is credible. References should not be the sole or even major deciding factor in determining to hire.

No...  It is one means of recruiting new employees but it is not the only one and isn't always the most effective means of recruiting new talent into an organization.

Yes this is very common, is headhunt recruitment, specially such types of recruitment can save time, reference check and recruitment expenditures, if the selected candidate met the position requirement.

Now-a -days it is global recruitment.It takes much more time for employer to make background checks for fresh recruiters.So,many MNC are recruiting their new recruits either by references or introductions of existing employees whose work and conduct are verified and proved beyond doubt  

Gowrisankar