Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It was designed to help developers take applications from concept to completion as swiftly as possible. Django emphasizes reusability, less code, and the principle of "Don't Repeat Yourself" (DRY).

1. Fast Development: Django was designed to help developers take applications from concept to completion as quickly as possible.
2. Secure: Django takes security seriously and helps developers avoid many common security mistakes, such as SQL injection, cross-site scripting, cross-site request forgery, and clickjacking.
3. Scalable: Django uses a component-based "shared-nothing" architecture, which means you can add hardware at any level (database servers, caching servers, or application servers).
4. Versatile: Django can be used to build almost any type of website, from content management systems and wikis to social networks and news sites.

• DRY (Don't Repeat Yourself): Django promotes the reuse of code and the reduction of redundancy.
• Explicit is better than implicit: Django's design philosophy is influenced by the Zen of Python, which emphasizes readability and simplicity.

Django follows the Model-View-Template (MVT) architectural pattern:

1. Model: Defines the data structure. It is the logical data layer.
2. View: Controls what data is presented and how it is displayed. It is the user interface layer.
3. Template: A text file that defines the structure or layout of a file (such as an HTML page). It is the presentation layer.

Let's look at a simple example to understand how Django works. We'll create a basic Django project and a simple app within it.

1. Install Django:

   pip install django
   

2. Create a Django Project:

   django-admin startproject mysite
   cd mysite
   

3. Create a Django App:

   python manage.py startapp myapp
   

4. Define a Model in myapp/models.py:

   from django.db import models
   
   class Person(models.Model):
       first_name = models.CharField(max_length=30)
       last_name = models.CharField(max_length=30)
   

5. Create a View in myapp/views.py:

   from django.http import HttpResponse
   
   def index(request):
       return HttpResponse("Hello, world. You're at the myapp index.")
   

6. Map the View to a URL in myapp/urls.py:

   from django.urls import path
   from . import views
   
   urlpatterns = [
       path('', views.index, name='index'),
   ]
   

7. Include the App's URL Configuration in mysite/urls.py:

   from django.contrib import admin
   from django.urls import include, path
   
   urlpatterns = [
       path('myapp/', include('myapp.urls')),
       path('admin/', admin.site.urls),
   ]
   

8. Run the Development Server:

   python manage.py runserver
   

9. Access the App: Open a web browser and go to http://127.0.0.1:8000/myapp/ to see the "Hello, world" message.

In this section, we introduced Django, a powerful and flexible web framework for Python. We discussed its key features, philosophy, and components. We also walked through a simple example to demonstrate how to set up a Django project and create a basic app. This foundation will help you understand the subsequent modules as we dive deeper into Django's capabilities and features.