1. Raspberry pi is a mini computer with Raspbian OS .
2. It can able to run multiple programs at a time
3. It can support Video,Audio,Ethernet,USB,HDMI
4. Supports C,C++,Python,Ruby
5. Interfacing with sensors needs installing of libraries and softwares
6. It have no storage on board, need an external SD card for storage.
7. Raspberry pi is expensive than arduino
1. Arduino is a microcontroller which is only a part of computer
2. It have no OS and it can able to run only one program again and again
3. Need external hardware for internet connectivity
4. Supports C,C++
5. Interfacing with sensors is easy and simple
6. Have internal storage
7. Consumes less power than raspberry pi.
Choosing Arduino or Raspberry pi is based on our requirements, So when need to do some projects based on sensors interfacing and analysis, arduino is cheap and best option whereas when needed to communicate with internet or performing multiple complex operations like video,audio etc.., then go for raspberry pi.