How do you plot one distribution on top of the other in R?

Welcome to Stack Overflow Irakli:

Here is some simple example of subplot using Plotly and subplots():

library(dplyr)
library(plotly)

# plot1
fig1 = plot_ly(data = mtcars, type = 'scatter', mode='markers', x = ~mpg, y= ~hp, name = "HP")

# plot2
fig2 = plot_ly(data = mtcars, type = 'scatter', mode= 'markers', x = ~mpg,y = ~drat, name="Drat")

subplot(fig1, fig2, shareX = T, nrows = 2)

Here is the output:

Another option for obtaining a similar plot can be achieved using cowplot package. Here is an example using the mtcars dataset.

library(cowplot)
library(ggplot2)

#Create first plot
p1<-ggplot(mtcars, aes(x = mpg, 
                   y = disp)) +
  geom_point() 

#Create second plot
p2<-ggplot(mtcars, aes(x = mpg, 
                       y = hp)) +
  geom_point()+ 
  #Remove x axis ticks, title and text
  theme(axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.title.x = element_blank())

#Create a canvas and draw the two plots with different sizes.
#x and y define the plot's lower left corner where each plot will be set (0-1)
# width and height can be interpreted as the proportion (0-1) of the original
#plot to be used to draw each plot
p3<-ggdraw()+
  draw_plot(p1,x=0,y=0,width=1,height=0.7)+
  draw_plot(p2,x=0,y=0.7,width=1,height=0.3)
p3