Julia - Displaying several plots in the same plot (not subplot) - plot

Question

Plotting several series in a same plot display is possible and also several subplots in a display. But I want several plots which can be completely different things (not necessarily a series or graph of a map) to be displayed exactly in one frame. How can I do that? In Maple you assign names for each plot like
P1:=...:, P2:= ...: and then using plots:-display(P1,P2,...); and it works. But I want to do this in Julia. Let's say I have the following plots as an example;
using Plots
pyplot()
x=[1,2,2,1,1]
y=[1,1,2,2,1]
plot(x,y)
p1=plot(x,y,fill=(0, :orange))
x2=[2,3,3,2,2]
y2=[2,2,3,3,2]
p2=plot(x2,y2,fill=(0, :yellow))
Now how to have both P1 and P2 in one plot? I don't one a shortcut or trick to write the output of this specific example with one plot line, note that my question is general, for example p2 can be a curve or something else, or I may have a forflow which generates a plot in each step and then I want to put all those shapes in one plot display at the end of the for loop.
Code for a simple example of trying to use plot!() for adding to a plot with arbitrary order.
using Plots
pyplot()
x=[1,2,2,1,1]
y=[1,1,2,2,1]
p1=plot(x,y,fill=(0, :orange))
x2=[2,3,3,2,2]
y2=[2,2,3,3,2]
p2=plot!(x2,y2,fill=(0, :orange))
p3=plot(x,y)
display(p2)
p5=plot!([1,2,2,1,1],[2,2,3,3,2],fill=(0, :green))
By running the above code I see the following plots respectively.
But what I expected to see is a plot with the green rectangle added inside the plot with the two orange rectangles.

Answer 1

The way to plot several series within the same set of axes is with the plot! function. Note the exclamation mark! It's part of the function name. While plot creates a new plot each time it is invoked, plot! will add the series to the current plot. Example:
plot(x, y)
plot!(x, z)
And if you are creating several plots at once, you can name them and refer to them in plot!:
p1 = plot(x, y)
plot!(p1, x, z)

Answer 2

Well, if you do that, what you will have is subplots, technically. That's what it means.
The syntax is
plot(p1, p2)

Answer 3

Sorry, I don't know how to plot a whole plot (conversely to a series) over an other plot.. For what it concerns the order of the plots, you can create as many plots as you want without display them and then display them wherever you want, e.g.:
using Plots
pyplot()
# Here we create independent plots, without displaying them:
x=[1,2,2,1,1]
y=[1,1,2,2,1]
p1=plot(x,y,fill=(0, :orange));
x2=[2,3,3,2,2]
y2=[2,2,3,3,2]
p2=plot(x2,y2,fill=(0, :orange));
p3=plot(x,y);
p5=plot([1,2,2,1,1],[2,2,3,3,2],fill=(0, :green));
# Here we display the plots (in the order we want):
println("P2:")
display(p2)
println("P3:")
display(p3)
println("P5:")
display(p5)
println("P1:")
display(p1)