creativestudiollc

It is a plug-in that get out non-administrators from the dashboard. 
It works just by enabling the plug-in.
管理者以外をダッシュボードから追い出すプラグインです。 
プラグインを有効にするだけで機能します。

get_out_dashboard

Manage 301 redirections, keep track of 404 errors, and improve your site, with no knowledge of Apache or Nginx needed.

zoltanlaczko

Using the password protection will give you extra security layer of protection from brute force hacking attacks. Additionally, it’s also an easy way to password protect your entire site, without needing to create separate WordPress users for each visitor.
When you enable the password protection, the user won’t be able to see anything – not even see the protected page – until he/she inserts the username/password. You can password protect the whole website, including the administrator pages; you can password protect the administrator pages; or you can password protect the WordPress login page.
The plugin options include:
<ul>
<li>Enabling/disabling the password protection to wp-login.php, WordPress admin pages.</li>
<li>Modifying the existing users: you can change any .htaccess user’s password and remove the users.</li>
<li>Create/modify an unlimited number of .htaccess users;</li>
<li>Protect your whole site, making it accessible to only those who have the .htaccess user.</li>
</ul>
This plugin is originally was based on <a href="https://wordpress.org/plugins/htaccess-site-access-control/" rel="ugc">.htaccess Site Access Control</a>. That plugin was working fine but it was abandoned for years and not compatible with the latest WordPress. Most part of the plugin were refactored and translated.

htaccess protect

htaccess protect - Protect your wordpress login or admin pages with password.

get_out_dashboard vs htaccess protect