Hi,
A W-2 hire by a company is a direct permanent hire, and W-2 refers to the IRS form that is filled out by the company and handed over to the employee when it's time to file taxes for the year.
A 1099 is also an IRS form, like the W-2, used by direct contractors - those who are not going through consulting companies. The 1099 is given to the direct contractor by the company that uses his or her services.
C2C is basically the subcontractor format of hire where a company routes the hire through a consulting company. A retainer or a certain amount of money, often called the "contracted amount," is given by the company to the consulting company. The consulting company then pays its employee who works for the company an amount after deducting taxes, its rate of profit for the contract, and any other legal charges. Essentially, the employee is an employee of the consulting company, and he or she will receive a W-2 from the consulting company.
SK