The visible universe, which includes all of space and time, is made up of about 4% atoms (mostly hydrogen and helium), 23% dark matter, and 73% dark energy.
The composition of the Universe is not well understood. It seems to be largely homogeneous in visible wavelengths: the same in every direction that we look in. However note that looking out into space we can see different objects and elements which were created at different points in the past when they were closer to earth - for example we can see distant galaxies which existed when they were closer to earth than they are now because light from them has taken billions of years to reach us.
