Tapa is a puzzle type originally created by Serkan Yürekli.
Shade black cells to form a single connected wall. Cells with numbers indicate the length of consecutive black cells in the adjacent cells. If there are multiple numbers in a cell, groups must be separated by at least one white cell. Cells with numbers can not be shaded, and black cells can not form a 2×2 square.
See this example puzzle and its only solution.