If you don't want to upload and replace complete application with your existing application then you need to do the following steps.
1- Before update must backup your database and all application folders and files.
2- You do not have to replace all the application folders every time.
- Just the following specific folders are important to replace and your application will be updated to latest version.
- Folders include
- app
- resources
- config
- database
- routes
- vendor
- js
- css
- Files include
- composer.json
3- Open your website or application in a browser, login as admin then go to settings -> general settings -> Important update option and click important. This will update your database.
Note: You must backup your application and database before applying update.