node.js - Getting more Dependency files while installing Express using npm -

while installing express using npm on nodejs. getting more dependency on node_modules folder.

ps c:\users\excrin-4\webstormprojects\fiducialcover> npm install express --save fiducialcover@1.0.0 c:\users\excrin-4\webstormprojects `-- express@4.13.4   +-- accepts@1.2.13   | +-- mime-types@2.1.9   | | `-- mime-db@1.21.0   | `-- negotiator@0.5.3   +-- array-flatten@1.1.1   +-- content-disposition@0.5.1   +-- content-type@1.0.1   +-- cookie@0.1.5   +-- cookie-signature@1.0.6   +-- debug@2.2.0   | `-- ms@0.7.1   +-- depd@1.1.0   +-- escape-html@1.0.3   +-- etag@1.7.0   +-- finalhandler@0.4.1   | `-- unpipe@1.0.0   +-- fresh@0.3.0   +-- merge-descriptors@1.0.1   +-- methods@1.1.2   +-- on-finished@2.3.0   | `-- ee-first@1.1.1   +-- parseurl@1.3.1   +-- path-to-regexp@0.1.7   +-- proxy-addr@1.0.10   | +-- forwarded@0.1.0   | `-- ipaddr.js@1.0.5   +-- qs@4.0.0   +-- range-parser@1.0.3   +-- send@0.13.1   | +-- destroy@1.0.4   | +-- http-errors@1.3.1   | | `-- inherits@2.0.1   | +-- mime@1.3.4   | `-- statuses@1.2.1   +-- serve-static@1.10.2   +-- type-is@1.6.10   | `-- media-typer@0.3.0   +-- utils-merge@1.0.0   `-- vary@1.0.1  npm warn fiducialcover@1.0.0 no repository field. ps c:\users\excrin-4\webstormprojects\fiducialcover> 

the above text command prompt, these files installed while install express uaing npm...i dont know do...

help me sort out problem...

nothing wrong that, express nodejs module, , have own dependencies, in order run, npm, downloads dependend dependencies recursively each module. if open node_modules/express/package.json following part:

 "dependencies": {     "accepts": "~1.2.12",     "array-flatten": "1.1.1",     "content-disposition": "0.5.0",     "content-type": "~1.0.1",     "cookie": "0.1.3",     "cookie-signature": "1.0.6",     "debug": "~2.2.0",     "depd": "~1.0.1",     "escape-html": "1.0.2",     "etag": "~1.7.0",     "finalhandler": "0.4.0",     "fresh": "0.3.0",     "merge-descriptors": "1.0.0",     "methods": "~1.1.1",     "on-finished": "~2.3.0",     "parseurl": "~1.3.0",     "path-to-regexp": "0.1.7",     "proxy-addr": "~1.0.8",     "qs": "4.0.0",     "range-parser": "~1.0.2",     "send": "0.13.0",     "serve-static": "~1.10.0",     "type-is": "~1.6.6",     "utils-merge": "1.0.0",     "vary": "~1.0.1"  } 

all of them dependencies express downloaded automatically npm.