White lines on MacBook Air screen after startup

Hi yesterday for the first time 3 or 4 white lines at the top of my screen appeared on my MacBook and then I updated it it went back to completely normal, I closed it opened it again because I had to do something. This morning I opened it there were a bunch of lines including the white ones making the screen look blurry but after it loaded all the white lines disappeared, I held down the power button till my Mac shut off and then reopened and it was compl Fine does anyone know why this may be the cause, like could it be something that runs when I turn on my Mac instantly or could it be another software thing or even hardware please help :)

[Re-Titled by Moderator]

Original Title: MacBook being weird