Private Equity (PE) distinguishes from other types of investments in five major steps.

First, PE professional's active involvement in projects. They identify, negotiate and structure the transaction, then monitor and advise the company. Therefore PE firms strongly contribute to the company's success. 

Second, PE invests for a specific time period. Usually a venture capital or private equity fund has a term around 7 to 13 years. In first 3 years all investments are supposed to be made and following years after gathering the success the investments are sold. Therefore PE manager always plans the exit strategy from the beginning. Often the transaction documents include the terms or the outline of PE's contemplated exit strategy. 

Third, PE capitalists usually invest in shares privately held. Plus, one of the most used exit strategy is selling the portfolio company's stocks into public market.

Fourth, PE demands reasonable return for their investments. They are not a lender just seeking to have a safe interest yield as they do not necessitate a bank letter of guarantee for security / collateral. Rather, they are hopping to share the portfolio company's success in comparably short period of time.

Fifth, the team. PE prefers highly dedicated and competant management team.