Checks for available updates to your version of LibreOffice. If a newer version is available, you can choose to download the update. After downloading, if you have write permissions for the installation directory, you can install the update.
Once the download starts, you see a progress bar and three buttons on the dialogue. You can pause and resume the download by clicking the Pause and Resume buttons. Click Cancel to abort the download and delete the partly downloaded file.
By default, downloads will be stored to your desktop. You can change the folder where the downloaded file will be stored in LibreOffice - PreferencesTools - Options - LibreOffice - Online Update.
After the download is complete, you can click Install to start the installation of the update. You see a confirmation dialogue, where you can choose to close LibreOffice.
Under some operation systems, it may be required to manually go to the download folder, unzip the download file, and start the setup script.
After installation of the update you can delete the download file to save space.