Skip to main content

Android Architecture Stack

Hello Everyone!


In this article we are discussing about the android architecture. It is essential for all the android application developers to understand the android architecture to get a clearer idea about the structure on which the application is made. From the exam point of view, the android architecture stack question has been asked several times (sometimes along with the Dalvik Virtual Machine).


Android operating system is a stack of software components which is roughly divided into five sections and four layers.

The five sections of android architecture are-

  1. Linux kernel
  2. Libraries
  3. Android Runtime
  4. Application Framework
  5. Applications

This is a layered architecture with each section having a different functionality.

A) Linux Kernel -

It is the bottom most layer of the architecture. This is the kernel on which android is based. This layer provides a level of abstraction between the hardware devices. It also contains all the low-level device for the various hardware components like camera, keypad, etc.

B) Libraries-

Libraries contain defined code for all the main features of android OS. The set of libraries provide open-source web browser engine WebKit which can be used for web browsing, library for SQLite database which is useful to store and access data for applications. Other libraries are for playing audio, video and for internal security. Some of them are android.text (for text manipulation on display), android.widget ( to use predefined UI components), and android.view (for intents).

C) Android Runtime-

The android runtime provides Dalvik Virtual machine which is used to convert the android code. DVM is similar to Java Virtual machine but enables android application to run its own process with its own instance of DVM. Dalvik is specifically designed for Android and optimized for battery- powered mobile devices which has limited memory and CPU resources.

The android runtime also provides a set of core libraries which allows the developers to write the application using Java programming language.

D) Application framework-

This Layer provides high level services in the form of Java classes.  The developers can make use of these services in the applications. The services included are Activity Manager, Context providers, resource manager, notification manager, etc.

E) Application-

This is the top most layer in the android architecture. In this layer, all the applications that are preinstalled or required for an application to run are present. Example- Phone, Contacts, Browser, Radio, Camera, Calculator, Settings, etc.

The applications which are installed later from application store are also present in this layer.  
Example- WhatsApp, Instagram, Truecaller, Zomato, etc.


Android Architecture Stack



Comments

Popular posts from this blog

50 + Interview Questions/Experiences of TCS DCA April 2021

Hello Everyone! This post is dedicated to the Interview Questions asked in TCS DCA. DCA which is Digital Capability Assessment is usually conducted for the internal employees of TCS who are selected for the Ninja profile. If DCA is cleared successfully, then the candidates are offered Digital profile. That means the profile changes from Assistant System Engineer to System Engineer . This year i.e., in 2021, TCS conducted DCA for the candidates who have received offer letter but not joined TCS as an employee yet. The original DCA which is conducted for internal employees has a different pattern and is not discussed in this post. Rather this post is dedicated to the DCA conducted in March and April 2021 for 2021 recruits. The DCA was conducted on 19 th and 20 th March 2021. The test had two coding questions. To sucessfully clear DCA, all the test cases of both the codes must be passed. In March DCA, a lot of students faced compile...

UML - Object Diagram for Hospital Management System

Hello Everyone! Here is an example of an Object Diagram for Hospital Management System. Problem Statement - The hospital wishes to maintain a database to assist with the administration of its wards and operating theatre and to maintain information related to its patients, surgeons and nurse. Most patients are assigned to a ward on admittance and each ward may contain many patients. However, consultants (senior surgeons) in the hospital may have private patients who are assigned to private room. A nurse may or may not be assigned to a ward and she cannot be assigned to more than one ward. A ward may have many nurses assigned to it. Each ward is dedicated to a particular type of patient. A nurse may or may not be assigned to a theatre and she cannot be assigned more than one theatre. Theatre may have many nurses assigned to it. A patient may have number of operations. The information to be recorded about the operation includes the type of operation, the patients, the surgeons involv...

UML - Activity Diagram for Vending Machine

Hello Everyone! Here is an example of an Activity Diagram of a Vending Machine. Problem Statement - A vending machine accepts coins for a variety of products. The user selects the drink from products available through selection panel. If the drink is available the price of the product will be displayed. The user then deposits the coins depending on the price of the product. Coin collector collects coin after stipulated time. The controller will compare the deposited coins with the price. If amount is less than the price then an error message will be displayed and all deposited coins will be dispensed by the dispenser. Otherwise the drink will be displayed by the drink dispenser. Check out other UML (Unified Modeling Language) Diagrams - Use Case Diagram   Class Diagram   Object Diagram   Sequence Diagram Collaboration Diagram   State Diagram   Component Diagram   Deployment Diagram