upsampling of a signal

i understood that upsampling is just increasing the sample rate of the signal. but how is it any way advantageous. can someone pls explain it in simple words since i'm a beginner.

[Moved]raised cosine filter ( upsampling and FIR)

a packet to be transmitted containing the header and payload is sent thro a raised cosine pulse shaped filter. this filter block has upsampling and FIR. I know that upsampling is like inserting zeros between samples. so if 1001100 is der wat is the advantage of adding zeros in between and also can someone pls tell me how are zeros added. In the sense say for differential encoding we xor the two bits of the sample and get the resulting output. same way for upsampling wat do we do. do we xor and or. also wont adding zero inbetween the sample be confusing of like wat is the original sample and wer zeros are added...
Also wat is FIR and and same way how is this also done. i saw for a FIR filter structure it had the input say for eg x[n] given to a block z^-1 (inverse z transform block) and then it was given to a multiplier block which multiplied it with filter coefficients. wat are these filter coefficients and finally all were added and the output was got. can anyone pls explain to me in simple words. since i am new to all this. so say for eg if we take inverse z transform of 1001100 wat will be the output?? can someone pls suggest a good link with simple word for z transform, upsampling and FIR if possible. Thank u

When you upsampled a signal, you can represent a signal which contains higher frequencies in digital. For instance, let's sya that you have a digital signal which is sampled at 10000 Hz. When you upsample it by the factor of 2, this signal become capable to represent the analog signals which are at 20000 Hz, without aliasing. That is the main advantage of upsampling, to increase frequency capacity of digital signal.

have a look at the Nyquist–Shannon sampling theorem
https://mathworld.wolfram.com/SamplingTheorem.html

or a more practical explaination
https://www.dspguide.com/ch3/2.htm