Land appreciation tax (mas shevach) is paid on the gain from the sale of a property. There are exemptions for the sale of a residential apartment, and the most common is the sole-apartment exemption.
The main conditions: you have owned the apartment for at least 18 months, and you have not sold another apartment under this exemption in the 18 months before the sale. For particularly expensive apartments, there is a cap on the exempt amount.
The exemption is claimed in the report filed with the Israel Tax Authority after signing. It is worth checking before signing, because it affects the price at which the sale makes sense for you.
Source: Real Estate Taxation (Appreciation and Acquisition) Law, 5723-1963
First published in Hebrew. Read the Hebrew original