When Minecraft receives an update, it's crucial to update your server as well so that players using the latest version of the game can connect. Fortunately, updating a Minecraft server is relatively straightforward. You can even save all configuration files to avoid having to reconfigure any settings in the new version.
Steps

Open your Minecraft Server folder.
- This is the folder containing all the files related to your server.

Back up essential configuration files.
- the following files to another location so you can quickly restore them after updating the server:
- banned-ips.txt
- banned-players.txt
- ops.txt
- server.properties

the "world" folder.
- this folder to the same location as the configuration files you just backed up so you can restore and access your saved world after the update.

the startup script file.
- If you use a script file to start your Minecraft server, copy this file to another location. You can restore it later to easily start your server.

Delete all remaining files in the folder.
- After backing up the important files to another location, delete all remaining files in the Minecraft Server folder. This step ensures that old files do not interfere with the new installation.

Download the new server file from Minecraft.net.
- Visit minecraft.net/download to download the server file for your operating system.
- Download the EXE file if you are using Windows.
- Download the JAR file if you are using OS X or Linux.

the new server file into your Minecraft Server folder.

Rename the server file.
- If you use a script or .bat file to start the server, rename the new server file to ensure compatibility with the old script. Remove the version number at the end of the new server file to match the old script.
- For example: Rename minecraft_server.1.8.exe to minecraft_server.exe.

Run the server file.
- Double-click the EXE or JAR file to launch the new server for the first time. All necessary files for the server's operation will be generated.

Shut down the server.
- Once the files are generated, close the server immediately.

Restore your backup files.
- Move the backed-up files, script, and the "world" folder back into the Minecraft Server folder.

Open the .eula.txt file.
- Locate the line eula=false and change it to eula=true. Save the file and exit the text editor.

Start your server.
- The update process is now complete.
Tips
- If you are running a CraftBukkit server, you may need to wait a few days after the update is released before a compatible CraftBukkit version becomes available.
