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• View. The icons in the View column open the enrichment plot () or the extra details report () (explanations below).
• Gene set ID. The Gene set IDs are based on the gene set file that was selected during set up. Each ID is a link to the geneontology.org page of the selected set. 
• Gene set size. Number of genes in the set (as specified in the gene set file).
• Enrichment score. The enrichment score score is the primary result of GSEA; it reflects the degree to which the current gene set is overrepresented at the top or the bottom of the ranked list of all the genes in the gene model (for details, see the References). The higher the enrichment score the more overrepresented (enriched) the gene set is.
• Normalised score. Normalisation of the enrichment score takes into account the size of the gene set. We recommend to use normalised values for filtering.
• P-value. P-value estimates the statistical significance of the enrichment score.
• FDR. False discovery rate (FDR) is used to control for multiple testing. We recommend to use FDR values for filtering.

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• Enrichment score. The algorithm walks down the ranked list of all the genes in the model, increasing the running sum each time when a gene in the current gene set is encountered. Conversely, the running-sum is decreased each time a gene not in the current gene set is encountered. The magnitude of the increment depends on the correlation of the gene with the experimental factor. The enrichment score is then the maximum deviation from zero encountered in the random walk (the summit of the curve).
• Gene set hits. Each column shows the location of a gene from the current gene set, within the ranked list of all the genes in the model.
• Rank metric. The plot shows the value of the ranking metric as you move down the ranked list of all the genes in the model. The ranking metric measures a gene’s correlation with a phenotype. A positive value of the metric indicates correlation with the first category (Numerator) and a negative value indicates correlation with the second category (Denominator). 

References

1. Subramanian A, Tamayo P, Mootha VK, et al. Gene set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles. Proc Natl Acad Sci U S A. 2005;102(43):15545-15550. doi:10.1073/pnas.0506580102
2. Mootha VK, Lindgren CM, Eriksson KF, et al. PGC-1alpha-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes. Nat Genet. 2003;34(3):267-273. doi:10.1038/ng1180