LP problem. $x_1$ is basic variable.$x_1=0$. Pivot is performed with the $x_1$ extracted from basis. Describe new basic feasible solution

Question

Suppose a problem is in canonical form and the associated basic feasible solution is degenerate, and $x_1$ is a basic variable with the value zero. The pivot operation is performed with the $x_1$ variable extracted from the basis. Describe the new basic feasible solution.

I am learning the Linear Programming by self-study. I didn't understand this problem and didn't know what the new basic feasible solution is.