The latest (2023) version of the Arduino Uno is faster and more powerful than the previous one (R3). It also includes an LED matrix and WiFi (plus BlueTooth) so that you can learn about the Internet of Things as well as the basics of robotics. This is a big step up from the previous version and yet the price is not significantly more. It is also possible to explore some simple embedded AI.

There is a really great tutorial by the DroneBot Workshop on the Arduino Uno Rev 4 Wifi and Minima

What’s on the board?

Briefly it has:

• 14 digital pins
• 6 analog pins
• an LED matrix
• WiFi and Bluetooth
• uses USB-C

Is it compatible with the previous version?

Mostly yes but one important difference is that the digital pins can only handle lower power draw of 8 mA which is considerably less than the Rev3, what that means is you would need to check how much current a particular component draws from those pins. An LED will need to have a higher resistor than previously. The form factor is the same, all the pins and holes are the same but there are new pins and components on the board.