I read in Wolfram documentation that ClearAll["`*"], clears values and definitions of all symbols in the current context. Not sure what they mean by current context. Does this mean, for example, that y, x, t, h, l, and v, would all be cleared, in the following program?

ClearAll["`*"]
h=1; l=10; v=1;
y[x_,t_]=Sum[(8h/(n^2Pi^2))(2Sin[n Pi/4]-Sin[n Pi/2])Sin[n Pi x/l]Cos[n Pi v*t/l],{n,1,40,1}];
y2=Table[Plot[y[x,t],{x,0,10}, AxesLabel->{"x","y[x,t]"},PlotLegends->StringJoin["t=", ToString[t]]],{t,0,2l/v,.02l/v}];
ListAnimate[y2]

If not, which symbols would be cleared by ClearAll["`"] given above?(I.e. which symbols would be considered the "current context")? Also, would this,

ClearAll["`Global"] 

clear every symbol in the program?