What does living paycheck to paycheck mean?

a Living paycheck to paycheck occurs when a person’s income is devoted to expenses, which means that little to no money is put in savings.
b When a person chooses to not deposit their paycheck, they are living paycheck to paycheck.
c Living paycheck to paycheck is an expression used to describe a situation when someone eagerly awaits their next paycheck to plan for the month’s expenses.
d Living paycheck to paycheck is an expression used to explain the situation in which a person cannot plan past the next paycheck due to financial and budgeting difficulties caused by outside circumstances.

d Living paycheck to paycheck is an expression used to explain the situation in which a person cannot plan past the next paycheck due to financial and budgeting difficulties caused by outside circumstances.