US Tax terms
A W2 hire by a company is a direct permanent hire and W2 refers to the IT form that is filled out by the company and handed over to the employee when its time to file the taxes for the year.
A 1099 is also a an IT form like the W2 that is used by direct contractors - ie not by those who are going thru' consulting companies. The 1099 is given to the direct contractor by the company that uses his or her services.
C2C is basically the sub-contractor format of hire where a comp routes the hire thru' a consulting company and a retainer or a certain amount of money, often called the "contracted amt" , is given by the company to the consulting company. The consulting company would be paying 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 comp and he or she will get a W2 from the consulting company.