FS1000A (Transmitter Part) Features & Technical Specifications:
Transmitter Model: FS1000A
Transmitting Frequency: 433.92MHz
Operating Voltage: 3V to 12V
Transmitting Power: 10mW to 40mW 16dBm
Transmitting Range: 20 to 100 meters through walls & 500 meters max in open area
Data Transfer Rate: <10 Kilo Bytes Per Second (Range drops above 2400 bytes per second)
Modulation Type: OOK
Current Consumption: 20 to 28mA
Current Consumption in Standby: 0mA
 
XY-MK-5V (Receiver Part) Features & Technical Specifications:
Receiver Model: XY-MK-5V
Transmitting Frequency: 433.92MHz
Operating Voltage: 5V
Receiving Sensitivity: 105DB
Modulation Type: OOK
Current Consumption in Standby: 4mA
 
Explanation / Description:
FS1000A (433 MHz/315 MHz/330 MHz RF Transmitter) & XY-MK-5V (433MHz/315MHz/330MHz RF Receiver) is a pair of low cost radio frequency module for one way wireless communication for arduino, raspberry pi and other platforms. This module is used by vast majority of electronics DIYers due to its low cost and easy implementation. The transmitter part can be operated from 3V to 12V and the maximum output can be achieved on 12V with 17cm antenna at both sides. However the receiver required stable 5V. These modules are available in three different frequencies which are 433MHz, 315MHz & 330MHz therefore you can buy according to your frequency requirements.  The max stable data transfer rate is 10kb per second.
The module only transmits one way because in this pair one is a RF transmitter and other is RF receiver. But it can be used for verity of purposes where there is not any requirement of two way communication for example wireless temperature sensor, switching home or office appliances, and transmitting data.  However if you want two way communication then you can also use other modules like HC-05, NRF24L01 etc.
 
Applications:
Anti theft products
Home security products
Home Automation
Office Automation
Garage door openers
Wireless car door locks
Wireless temperature sensors
Short distance data sending
 
Where To Use This module
FS1000A 433MHZ RF transmitter & XY-MK-5V receiver module can be used in any project where there is a requirement to send data through air under short distances. For example if you require a continuous temperature monitoring inside or your house or outside, temperature monitoring of machines running in factories. Moreover it can also be used to control electronic appliances in home or in office, making home or office security projects, door locks etc.
 
How To Use This module
Using FS1000A 433MHZ RF transmitter & XY-MK-5V receiver module is very easy, for using this module you have to have two platforms attached on each side for example if you are using arduino for building your project then you must have two arduino boards in which one should be connected with the transmitter and the other with the receiver. The connection of the transmitter and receiver is not very difficult you only have to connect three wires of the transmitter with one arduino board and three wires of the receiver with other arduino board. There are also two different parts of codes available for the project one for transmitter that can be saved in the arduino attached with the transmitter and other part of code should be saved in the arduino board connected with the receiver. The above simple explanation of how to use the RF module will work on any project you are building using these modules but the code and wiring may be different in different projects and you will get that information in the details of the project you are building you will find many projects using this module with guide and codes online.
 
Recources:
1. Complete Guide for RF 433MHz Transmitter/Receiver Module With Arduino
2. How 433MHz RF Tx-Rx Modules Work & Interface with Arduino