قطعة الارض = plot number
القسم = subdivision / part
مربع = block

to divide into several parts; : to divide (a tract of land) into building lots. Successfully subdividing your land into residential lots
https://blog.lotnetwork.com/subdividing-land-tips-for-landow...

the most common methods used to describe land are by reference to a lot and/or block within an existing subdivision,
https://blog.landcentral.com/land-university-blog/understand...

Sometimes they refer to it as subdivided blocks where the block is divided into parts.

grid as a system of subdivided blocks
https://www.gothamcenter.org/blog/gridplan09exp


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Note added at 4 hrs (2024-01-27 20:54:22 GMT)
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Subdivisions are the act of dividing land into pieces that are easier to sell or otherwise develop,
Subdivisions may also be for the purpose of commercial or industrial development,
https://en.wikipedia.org/wiki/Subdivision_(land)