>>12327335They have one or more antennae that is used to send and receive wireless data. If needed, satellites may have small thrusters to be used for alignment. Depending on the use of the satellite, such as in the case of a scientific satellite, it may have cameras or probes for collecting data, which may then be wirelessly sent back to Earth.
Wireless data is in the form of electromagnetic radiation. All electromagnetic radiation falls somewhere under the electromagnetic spectrum, including the radio you might pick up in a car, to 5G internet, and far more besides. A satellite's wireless communication may be simply said to work the same as a cell phone.
The exact frequency (frequency being position on the electromagnetic spectrum) used will depend on what the satellite will be doing. However, because of how the Earth's atmosphere works, certain frequencies are more viable than others.
>>12327433Imagine the wind. You know it's air causing it, but you can't see it, and usually don't even have to think about that fact that its there.
Electromagnetic radiation is similar - it's there, but you're unlikely to consciously notice. If you're able to use eyes to see, visible light is part of that spectrum.
To put it simply, much like Morse code which uses a series of beeps that make a coherent language, with control over an emitter, it is possible to "send" radiation in controlled pulses. These pulses may then be interpreted, and a message may be understood.
