For posting blog on website, admins and authors login to their installed WordPress CMS.
WordPress, by default shows up its own logo above the username and password fields as shown below,
You can easily customize it by replacing the default WordPress logo with your own logo.
Here is how you can do this,
1. First choose an image that you want to put on the login page. Name it logo-login.png.
2. Login to your web hosting using FileZilla FTP and navigate to wordpress/wp-admin/images folder.
3. Drag and drop your image (logo-login.png) to the folder.
[Here we basically override the default WordPress logo file, so click ‘OK’ when a message asking for overriding appears.]
4. That’s all! Now visit your website’s login page, it’ll have a logo that you have just uploaded rather than the default WordPress logo.
Here is how CyberPassion’s login page looks after customizing,