What is a house cusp?
The line where one house ends and the next begins, given as a degree of a sign. The 1st cusp is the Ascendant and the 10th is the Midheaven. A planet within a degree or two of a cusp is usually read as belonging to the house it is about to enter.
Where you see this in OrbHeaven
Your own chart is calculated from your birth details, and this definition is written out again there with your numbers in it rather than in the abstract. The chart, the glossary and thirty days of dated timeline are free, and nothing here is charged per question.
About a minute. Birth time optional, and no account until after you have seen it.
The chart
What the picture is, and what the numbers on it are measuring.