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  "body": "\n## Summary\n\nA site is a [[category|A2DE66937D]] together with a [[Grothendieck topology|GDRFSJ8E2B]] on it.\nIt is the setting in which [[sheaves|RT8A8FJ566]], sheafification and sheaf cohomology make sense beyond topological spaces.\nThe open sets of a topological space form a site, and so do the étale maps into a scheme, which give étale cohomology.\nThe category of sheaves on a small site is a [[Grothendieck topos|S3YVE24AQK]].\n\n## Explanations\n\n### L1 human\n\nA site is a \"generalized space\" described by its pieces and by the rule saying which families of pieces cover a piece.\nThe pieces need not be subsets; they can be maps from other objects.\nFor example, the open sets of the real line, with the usual covers, form a site, and its sheaves are the usual sheaves on $\\R$.\n",
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