The Free On-line Dictionary of Computing (30 December 2018):

Celeron

    Intel Corporation's trade name for its family of
   Pentium II microprocessors meant for use in low-end
   computers.

   The Celeron is constructed on the 0.25 micron Deschutes base.
   Clock rates of 266, 300 and 333 MHz are supported.  It is
   built on the same daughterboard as the Pentium II without
   the black plastic case and heat sink.  Four Celeron models
   are in production as of October 1998.  The 266 and 300 MHz
   models are essentially Pentium II CPUs without the Level 2
   cache RAM.  The 300A and 333 MHz Celerons include 128k of
   Level 2 cache.

   A special mounting bracket on the motherboard is used to
   secure the Celeron in place in its standard 242-pin Slot 1
   socket.  Intel calls the caseless design SEPP (Single Edge
   Processor Package) to differentiate it from the Pentium II SEC
   (Single Edge Cartridge).  Some believe that the real purpose
   for the different mounting configurations is to prevent users
   from placing lower cost processors onto Pentium II
   motherboards.

   A Celeron is about one third the cost of a similar speed
   Pentium II.  Hardware hackers claim that the Celeron 300
   without Level 2 cache could be overclocked to perform as
   well as a Pentium II at a fraction of the price.

   (http://intel.com/Celeron/).

   Tom's Hardware (http://www2.tomshardware.com/cpuslot1.html).

   (1998-10-06)