It is very much required to provide same URL to access your content means www.yoursite.com/page.html and www.yoursite.com/page.html/ treated as different-2 URLs by Search Engines and It makes down search engine indexing(SEO Level). To avoid this you need to add trailing slash with htaccess at end of each URL of your website.
Add these few lines in .htaccess file to add trailing slash at end of each URL:
# Add a trailing slash
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !#
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ http://www.yoursite.com/$1/ [L,R=301]Note→According to Google’s webmaster guidelines you need to add trailing slash with htaccess at end of every url because google treats both URLs with slash and without slash as different-2 URL and not indexing these URLs because of duplicate content. Read more