The Celeron was crated by Intel to compete with the low-cost AMD K6 and Cyrix processors. The original version was simply a Pentium II processor with no L2 Cache and supported a 66MHz system bus. Later versions, starting with some of the 300MHz processors, included 128KB cache running at the same speed as the processor. Today One can buy Intel Celeron with speeds up to 1.2 GHz.
Today's Celeron processors come in a Single Edge Contact Cartridge 2 (SECC2).