The Pentium can switch between four different memory management modes.
The pentium normally uses a Segmented memory organization.
The Pentium's memory is byte addressable
The Pentium's address length is 32-bits so it can support up to 4 Gigabytes without segmentation and 64 Terabytes with segmentation.
The Pentium's memory is divided up into segments.
Each segment register can hold a 16 bit address so each segment is 64KB.
Each register holds the address of the top of the segment.
The Pentium uses Segmentation normally over paging because the hardware of the CPU is made to support segmentation specificly.