when cooking, stove top or GRILL—say when the packagin says cook on “medium-high” ? what does this mean? is this medium heat or in between medium and high. for example , on my oven stovetop, there is low, medium, high —- what does medium-low, medium-high, medium, mean?

is medium heat AND medium-high heat samething ? or different ? medium is medium and medium-high is inbetween medium and high . please clarify

please help.
i just started cookin.. i ate a thick steak cooked on medium heat for 6min per side..yesterday when insttrcution said use medium-high.
i thought medium & medium-high were samething just different wording. did i eat undercooked meat with bacteria?>