Gross income is what you earn before any deductions. Net income — take-home pay — is what actually lands in your account after tax and payroll deductions.
Almost every budgeting mistake starts by confusing the two. A rule like 50/30/20 applied to gross income produces category limits you cannot actually fund, because a meaningful share of that money was never yours to allocate. Job offers are usually quoted gross, which is also why comparing two offers in different countries or contract types requires converting both to net before the comparison means anything.