Names should describe what the variable contains. Compare these: python x = 1000 monthly_salary = 1000 Both store , but monthly_salary tells you what that number means.
When you read the code later (or someone else reads it), the meaning is clear. Avoid single letters except for simple loop counters or math formulas where convention dictates them. i for an index is fine. n for a count is fine.
But x for a user's email address? That's confusing. Good names save debugging time. You'll thank yourself later.