Einstein's universe is Einstein's stationary (or "static" as some cosmologists call it) model universe of 1917.
To keep Einstein's field equation of this stationary model stable, and not knowing yet about the "Hubble time dilation", discovered by Edwin Hubble over a decade later, and suggesting to some cosmologists that the universe might be expanding. Einstein then added his "cosmological constant" that stopped the alleged expansion of his model universe. Later he called this cosmological constant "the biggest blunder of his life" as there was a simpler way of getting rid of illusion of expansion.
In 1985 the "cosmological constant" turned out not to be needed at all since it turned out that the Hubble redshift is not caused by expansion of the universe but by time runing slower at deep space galaxies in curved space, which simmulated accelerating expansion of space.