# npm package-lock.json file in JavaScript

A `package.json` file usually contains the range of package versions that are installed for our project. This can lead to some problems if we decide to move the project and re-install after a while. In this case, since some time has passed since the previous installation, newer versions of the packages will be installed, which can lead to instability in our project work.

Therefore, in addition to the `package.json` file, npm automatically creates the `package-lock.json` file that describes all the installed dependencies (including the dependencies of our project dependencies) and their exact versions. In this case, when reinstalling the project, exactly those versions that were installed earlier will be installed, and not others.

Install the jQuery library. Examine the resulting `package-lock.json` file.

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