Probashi Kallyan Bank Programmer Written Exam: 2019 (AUST)প্রশ্ন ও সমাধান

A hypervisor (Virtual Machine Monitor) is software that creates and runs virtual machines (VMs) by abstracting physical hardware. There are two types:

	Type 1 (Bare-metal)	Type 2 (Hosted)
Runs on	Directly on physical hardware	On top of a host OS
Examples	VMware ESXi, Microsoft Hyper-V, Xen	VMware Workstation, Oracle VirtualBox, Parallels
Performance	Higher (near-native)	Lower (extra OS layer overhead)
Use case	Data centres, servers, cloud	Desktops, development/testing
Dependency	Independent of any host OS	Depends on the host OS for drivers/resources

Type 2 hypervisor in detail: it is installed as an ordinary application on top of a conventional operating system (Windows, Linux, macOS). It relies on the host OS to manage the underlying hardware (CPU scheduling, memory, drivers) and presents virtualized hardware to guest VMs running above it.

graph TD
  A[Guest OS 1] --> H[Type 2 Hypervisor]
  B[Guest OS 2] --> H
  H --> OS[Host Operating System]
  OS --> HW[Physical Hardware]

Advantages: easy to install/use; good for running a few VMs on a personal machine for testing/development.
Disadvantages: slower than Type 1 because of the extra host-OS layer, and a host OS crash affects all VMs.

Exam takeaway: a Type 2 hypervisor runs on a host OS (not directly on hardware) — simple and flexible, but lower performance than Type 1; used mainly for desktop virtualization.

All three are jQuery's AJAX helpers, but they differ in configurability and what they do with the response.

Method	Configurability	Request Type	What It Does With Response
$.ajax()	Full control — headers, timeout, error handlers, data type	Any (GET/POST/PUT...)	You handle the response yourself in a callback
$.get()	Shorthand for $.ajax() with sensible defaults	GET only	Passes response to a callback function
$.load()	Simplified, tied to a specific DOM element	GET (or POST if data is passed)	Automatically inserts the returned HTML into a selected element

Examples:

// $.ajax() - full control
$.ajax({
  url: 'result.html',
  method: 'GET',
  success: function(data) { $('#stage').html(data); }
});

// $.get() - simple GET request
$.get('demo.php', function(data, status) {
  console.log(data, status);
});

// $.load() - fetch + auto-insert into the element
$('#stage').load('result.html');

When to use which:

• Use $.ajax() when you need custom headers, error handling, or non-GET verbs.
• Use $.get() for a quick GET request where you'll handle the data yourself.
• Use $.load() when the entire purpose of the call is to drop returned HTML straight into a page element.

Exam takeaway: $.load() is the odd one out — it's tied to a jQuery-wrapped element and inserts markup directly, while $.ajax()/$.get() just deliver data to your own callback; $.get() is simply $.ajax() with GET-specific defaults pre-filled in.