It is sometimes called a distance sensor. The motion sensor (part 9583) can detect objects very roughly up to 15 cm away, depending on the shape of the object and other properties (reflection, colour, etc.). The following descriptions have been copied from LEGO Engineering.

The difference between the regular SBrick and the SBrick Plus is that the Plus version is able to communicate with the two available WeDo 1.0 sensors: The SBrick Plus is fully compatible with the SBrick. Well, let me tell you a is! The form factor of the SBrick Plus has remained the same. Sounds like an SBrick with additional functionality. Two years later a new family member is introduced, the SBrick Plus. The Kickstarter project reached its goal and SBrick was born. I would expect the large PU hub to behave similarly to the small one.It feels like yesterday, but it's already over two years ago that Vengit introduced us to the SBrick! The SBrick is a versatile LEGO compatible component, used to control your PF elements via a smart phone or tablet. Given that using the Spike motor with the Boost hub did not work, but using the the WeDo motor did, I am really unsure about what to expect re. I do not own a large or extra large PoweredUp motor and no large PoweredUp hub. The only thing that is missing then is the position readout. Although you can use the Spike motors reasonably well with the PoweredUp app and the small (Bat Mobile) PoweredUp hub. It seems you cannot use Spike motors or sensors with the PoweredUp app and the Boost hub, or at least I could not. This is a property of the motor, the Boost motor has all these abilities when using the PoweredUp app. The WeDo motor only offers 'Set power to X' functionality, no 'Set power to X and run for Y seconds' or 'Go to position' or 'Turn for 5 rotations'. But you always have to set the ports explicitely and remember that the external ports on the Boost hub are ports C and D. If you use the PoweredUp app, you can use WeDo sensors and WeDo motors as well. My impression is that the Boost app can work with one Boost hub, one Boost motor and one Boost color/distance sensor.

Lego wedo sensors