When running a Java application it is mandatory that the JRE version to match or to be higher that the JDK version used to compile the application.
You will get the "Unsupported major.minor version 52.0" error when trying to run an Java 1.8 application using a lower version of Java.
The abstract keyword is used in Java for abstraction. The abstraction is the process of selecting data and displaying only the relevant details to the object. If helps to reduce the programing complexity and the efort.
Keywords are special words in the programing language which have reserved use in the language. Keywords may not be used as identifiers in Java; for example you cannot declare a field whose name is a keyword.
On-page SEO or On-site SEO is the process of optimizing the web page content for search engines and users. The practices for on-page SEO include optimizing title tags, content, internal links and URLs.
The sitemap's a file place on your website that will enable Google and other search engines to crawl better and understand the structure of the site. Sitemaps also tell search engines which pages on your site are most important. It's a binder of your website's content.
A robots.txt file tells search engine crawlers which pages or files the crawler can or can't request from your site.
This is used mainly to avoid overloading your site with requests; it is not a mechanism for keeping a web page out
of Google. To keep a web page out of Google, you should use
noindex directives, or to password-protect