App components are an entry point through which the system or a user can enter into your app. Components There are four different types of app components: ActivitiesServicesBroadcast receiversContent providers 1.Activities Android Activity is Front end view of an app.It represents a single screen with a user interface. For example, an whatsapp app might have one activity that shows a list of all contacts, another activity to show all chats, and another activity to update status. Although the activities work together to form a cohesive user experience in the whatsapp app, each one is independent of the others. Intent: An Intent is a simple message object that is used to communicate between android components such as activities, content providers, broadcast receivers and services. Intents are also

An elevator is a platform that is used for lifting people up and down in the buildings. Elevators are part of almost all commercial and residential buildings.It is a vertical transport vehicle that efficiently moves people or goods between floor of a building. Elevators are generally power by electric motors that drive traction cables and counter weight with the help of motors.The overall control is done by control system. Key parts of elevator are: .One or more cars(metal boxes) that raise up and down. .Counter weight that balance the car. .An electric motor that hoist the car up and down,including a braking system. .A system of strong metal cable and pulley running between the car and the motor.

From several 100 years back , elevators were created that are for water driven mechanism.In 18's new invented elevators were created that for lifting high weight materials. Depending upon applications now modifications are happening in elevators. Elevators are convenient way for vertical Transportation in safer mode.Also it saves time and energy efficiently. It has capacity to bare high weight materials.shortly it acts as carrier for transportation. In world-wide there are several manufactures for elevators.Depending upon applications they are manipulating features included it. Top manufacturers of Elevators from Pune 1.Orbitech Elevators.2.Tower Elevators.3.Force Technologies.4.Avicon Elevators pvt ltd.5.Idea elevators company.6.Escon elevators.7.OTIS Elevators co ltd.8.Escon Elevators. Types of Elevator Roped hydraulic elevator.Prematic vaccum elevator.Counterweight chain drive elevator.Traction drive elevator. Working of elevator Basic structure of elevator 1)Counterweight: By exerting opposite force it provides balance

Elevator is nothing but one or more cars which are metal boxes which rise up and down for vertical transport of people or goods. Parts: Car(metal boxes)CounterweightElectric motor ,Braking systemStrong metal cables and pulleysControl SystemSwitches and SensorsSafety system Basic diagram of elevator system It uses motor for hoisting the car. For vertical movement it uses strong metal cables and pulleys. There are different types of elevators based upon different factors like technologies used,application,speed,hoist mechanism used,whether it carries people or good ,control system used,etc. Two types of elevators that are most commonly used in residential and commercial buildings are: Traction elevators and Hydraulic elevators.For high speed and high rising modern buildings,traction elevators are used.Traction elevators are also energy efficient