Friday, 27 March 2020

What is java runtime environment JRE

 What is java runtime environment.

JRE stands for Java Runtime Environment. JDK ( stands for java development kit ) internally consists of JRE. JRE  has JVM ( java runtime environment ).  JRE ( Java Runtime Environment ) is required to run java programs. without JRE we cant run our java programs.

Thursday, 26 March 2020

What is html? | Points on HTML

What is HTML?

  •    It is a language which describes the webpage.  
  •    It is very simple and easy to learn.
  •   It is a markup language.
  •   It is not a programming language like c, c++, java etc.

What is the full form of HTML?

HTML stands for Hypertext markup language used for developing web pages.


These files are saved as <any name >.html  i.e.; these files will have file extension as .html ( as an example  first.html). These HTML files have to be opened using browsers (firefox, chrome, opera etc ) to see the output.  All browsers support HTML.  The web browser (firefox, chrome, opera etc ) does not display the HTML tags.

The purpose of using the html is for developing webpages.
We can develop very good web applications if we combine HTML with CSS, JavaScript. CSS stands for cascading style sheet.

HTML tags:

  • HTML has so many tags. We can have any number of tags in a webpage and can repeat them as per requirement.
  •  These tags are enclosed in angular brackets example  <html>. Tags can have attributes, which gives the additional information to the content of tag.

HTML is case insensitive language i.e.; <html> and <HTML> both are same.
Most of the elements in html have a beginning tag and an ending. Some commonly used tags are <B>bold</B>, <i>italic </i> ,<P> paragraph </p> , etc.

  <html> is the root tag in web page. It also has an ending/ closing tag </html>

  <head> tag will start immediately after the starting  <html> tag and end directly before the opening body tag.
    
  
This head tag has so many sub tags like <title>, <script>, <link>, <meta>, <script>, etc.

   <title>title of page</title> is used for title of page. Title tag will come under <head> tag.
  For example:
    <head>
            <title>title of the page here </title>
    </head>
All tags will not have ending tags for example <br>.
<body> it is called as body tag. It also has ending tag </body>. This tag consists of all the contents of a webpage.

Anyone who wants to develop web based applications, web pages has to learn html.
A web page can have any kind of data like text, images, forms, data in the form of table, links, images etc.

What are some uses of html are:
  •  Web document Creation 
  •  Web pages development
  •  Cutting edge feature
  •  Internet navigation
  •  Creating web sites
Html comes with so many versions.

Wednesday, 25 March 2020

JVM | Java virtual machine


JVM

JVM stands for java virtual machine. The virtual machine of java  enables a computer to run our Java programs  that are  compiled to Java bytecode.
Before it is executing  JVM verifies the bytecode .
Java virtual machine (JVM) provides runtime environment.
Java virtual machine converts bytecode into machines language. It is a part of Java RunEnvironment (JRE).


 Here is how JVM works:

First, we have to write java program and then save this java program and then  compile the java program if no compilations are there then we get  bytecode.
 This bytecode gets interpreted on different machines.

Java virtual machine (JVM) is responsible for allocating memory space.