Arduino and Raspberry Pi are totally different the one is Microcontroller and the other one is a mini computer with Operating system support.
① Arduino is good but it,s Microcontroller not a computer and we all know that Microcontroller can do one task at a time have no ability of Multitasking while Raspberry Pi has the ability of Multitasking Because Raspberry Pi is not a microcontroller it,s a fully functional Linux operating system.
② Arduino Clock speed is not much faster and good as compared to Raspberry Pi you can see clearly from the chart given below it shows that Raspberry Pi clock speed is 42 times faster than Arduino.
③ Arduino do not support USB ports, external sd card and also a wireless connectivity with internet while Raspberry Pi supports USB ports, external Sd card and had the ability to connect wirelessly with the internet it,s independent.
④ There are many Points where it shows clearly that Raspberry Pi is Best and Arduino Game is over! This is not True Arduino Game is not Over Still Uncountable students and Electronics Lovers Likes Arduino Because due to it,s simplicity if you want to write a program for to blink a led so it Arduino it,s so simple you can write a code in less than 3 minutes and will take 2 minutes more to compile it but in Raspberry Pi it,s just like to watch a Horror movie alone lol at Raspberry Pi first you would need to install an operating system Linux os it,s not an easy job to use Linux and also some code Libraries i think it,s hard job for beginners to do their first project by using Raspberry Pi .
⑤ Arduino is Best for Students especially for the Beginners because Arduino help to make thousands of school or university projects using Arduino like
senor, motor, robot, security, bionic arm, Matrix Dot led e.t.c
Arduino is Best and will remain best for The Beginners it,s treasure for the Beginners they can learn more and more by using Arduino .i preferred Raspberry Pi for the Professionals, not for the Beginners.