Find all four solutions to x^2 Ξ 133 (mod 143). (Note that 143 = 11 . 13)

Can anyone tell me what does mean here in this question ? what does mean by Ξ ??

And what does mean by mod 143 ??

And why it sasy 143 = 11.13 ??

Please tell me someone if you know !!1

Can anyone tell me what does mean here in this question ? what does mean by Ξ ??

And what does mean by mod 143 ??

And why it sasy 143 = 11.13 ??

Please tell me someone if you know !!1