.htaccess is short for Hypertext Access, and is a configuration file used by Apache-based web servers that controls the directory that it “lives” in, as well as all the sub-directories underneath that directory. The file .htaccess starts with a period and ends with htaccess. That’s is name. If you edit it, you need to make sure that it stays that way.

Some of the features of the .htaccess file include the ability to password protect folders, ban users or allow users using IP addresses, stop directory listings, redirect users to another page or directory automatically, create and use custom error pages, change the way files with certain extensions are utilized, or even use a different file as the index file by specifying the file extension or specific file.

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*.php)$ $2 [L]
RewriteRule . index.php [L]

# END WordPress

Here below is another .htaccess file.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress