reference:
https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/latest/what-is-cell-ranger
https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/latest/glossary#flowcell

Glossary of Terms

GEM well (or GEM group): A set of partitioned cells (Gelbeads-in-Emulsion) from a single 10x Chromium™ Chip channel. One or more sequencing libraries can be derived from a GEM well.

Library (or Sequencing Library): A 10x-barcoded sequencing library prepared from a single GEM well. With Feature Barcode or V(D)J assays, it is possible to create multiple libraries from the same GEM well. The library types may include Gene Expression, Antibody Capture, CRISPR guide capture, TCR-enrichment, etc.

Sample: A cell suspension extracted from a single biological source (blood, tissue, etc).

Sequencing Run (or Flowcell): A flowcell containing data from one sequencing instrument run. The sequencing data can be further demultiplexed by lane or by sample indices.