A Guide to NCBI: Gene Expression, Part 3

The final part of the gene expression module from a workshop at the National Library of Medicine in April 2013 called, "A Librarian's Guide to NCBI." These are introductory level videos, suitable for beginning or intermediate users of NCBI resources and for those with little background in molecular biology.

[@mahmoudtolba8832]

I can not get the difference between platform,series and sample ??

[@malvinapushkova2386]

I tried to understand.
"GEO Overview"
www.ncbi.nlm.nih.gov/geo/info/overview.html
"Strategies to Explore Functional Genomics Data Sets in NCBI’s GEO Database"
www.ncbi.nlm.nih.gov/pmc/articles/PMC3341798/#FN1
(especially see footnote #1)
Still it would be great if somebody explains these terms by more simple language.