Intel Core 2 Duo E8800 (ES)
Intel Core 2 Duo E6200 (ES)
Intel Core 2 Duo E7700
Intel Pentium II 266 (0,35µ)
Intel Core 2 Duo E7800
Celeron is the marketing name used by Intel for its low-end processors.
This brand name was invented during Pentium II era, and is still used today.
But, if when they were first released, Celeron were low-end versions of Pentium II, it is not true anymore : for each architecture released since Pentium II, there have been Celeron versions.
So, there is not only one Celeron kind, but several, each based on different core architecture, with almost nothing in common :
P6 Architecture
Netburst Architecture
Mobile Architecture
Core Architecture
Nehalem Architecture
Sandy Bridge Architecture
Haswell Architecture
Silvermont Architecture
Skylake Architecture
Goldmont Architecture
Golden Cove Architecture
Golden Cove/Gracemont Architecture