I'm having trouble understanding the local variables of the Block command. Thanks for your attention

(*example one*)
(*This is said in the documentation*)
(*Blocklocalizes values only;it does not create new symbols*)
(*I don't understand the previous sentence*)
ClearAll["Global`*"];
Block[{x}, x]
Block[{x}, Print[x]]

(*example two*)
(*This is an example of the documentation.*)
(*But if one of x or y is global the example does not work*)

ClearAll["Global`*"];
Block[{f = Sin[x + I y]},  ParametricPlot[Evaluate[{Re[f], Im[f]}], {x, -Pi, Pi}, {y, -2, 2},   Mesh -> 10]]

(*example three*)
(*I would like the block to work regardless of whether x is global or not*)

ClearAll["Global`*"];
Block[{x},
 TraditionalForm@TextCell[Column[{
     Row[{x, " = ", 5}]    (*I want x to always be a symbol*)
     }, Spacings -> 0.5], "Text", FontFamily -> "Palatino",    FontSize -> 18]
 ]