Shamayim, the Hebrew word for heaven, is found 313 times in the Old Testament. It can be translated either to mean "sky" or "abode of the stars."
In the New Testament the word in Greek is "ouranos" and is found 247 times, and can mean virtually the same as the Hebrew word. Though with the Greek language being a literal language and not emotional (as the Hebrew language is), there are a few additional definitions. Such as "the universe" or "the world" or "the region where the clouds and the tempests gather, and where thunder and lightning are produced." Another definition more closely touches on our concept of actual "heaven," seen here: "the region above the sidereal heavens, the seat of order of things eternal and consummately perfect where God dwells and other heavenly beings."
Jesus talks about heaven a lot in His parables throughout the four gospels, but He never specifically describes what heaven is like. New Jerusalem on the other hand is described in detail in Revelation 21:9-21, and will essentially be our dwelling place at the end of time.
Grace to you!