How to add white gaussian noise to a signal?

I want to add white gaussian noise to a signal x(t) in matlab but i'm quite confused

should i use awgn() function or x+sigma*randn(size(x))+mu

can someone please explain to me what's the difference between the 2 methods and which one should i use ?

Thank you so much!

[Adam Danz]

randn merely samples from a normal distribution with mean 0 and std 1. For example, histogram(randn(1,20000))

This answer exaplains the awgn function well,

https://www.mathworks.com/matlabcentral/answers/40772-snr-in-awgn#answer_50412