Tuesday's tax deadline is fast approaching, which means you should have received all your tax forms already. If you haven't looked at them yet, all those numbers and letters — W-2, W-9, 1099 — can start to feel like a mishmash very quickly.

Some forms were sent directly to you and there's no further action you need to take besides, in some cases, documenting it in your overall tax return. There are other tax forms, though, you'll need to complete yourself.

Many types of forms you're required to complete will depend on your employment status (i.e. whether you're self-employed or not), but there are a lot of other determining factors besides that.

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So before you get deep into the nitty-gritty , it's worth taking a moment to understand the purpose of the many forms you'll likely interact with.

What is a W-9 used for?

A W-9 is a type of form where you provide identifying information such as your Social Security number or tax identification number.

A typical reason for filling out a W-9 is if you're an independent contractor, freelancer or gig worker likely to earn more than $600. You may also be asked to fill out a W-9 when you open an interest-bearing bank account or other kinds of financial accounts that provide extra income.

This form doesn't get sent to the Internal Revenue Service. But the information you provide on a W-9 will be used to prepare other forms, namely 1099s.

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Is a W-9 the same as a 1099?

The main difference between a W-9 and 1099 is that you fill out a W-9 while the business or entity you're earning income from fills out the 1099. In most cases, you should have received the form by Jan 31.

A 1099 form is used to report income that isn't directly earned through an employer. Because there are many different ways to make money outside of a traditional job, there are several types of 1099 forms.

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Common1099s you might see: 1099-G, 1099-K, 1099-R, 1099-Div

Some of the most common 1099s you may receive:

• 1099-G: details any state or local tax refund last year that's considered income.

• 1099-K: summarizes any income you earned $20,000 from more than 200 transactions on sites like Etsy, Airbnb and Venmo.

• 1099-R: reports distributions of $10 or more from various types of retirement plans, annuities, pensions, insurance contracts, or other similar accounts.

• 1099-Div: used by banks and other financial institutions to report dividends and other distributions to taxpayers and to the IRS.

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What is a W-4 and what is it used for?

A W-4 is a form you're required to fill out when you work directly for an employer.

It tells your employer how much federal income tax should be withheld from your paycheck based on factors like whether you're married and filing a joint return; if you have dependents to claim; and if you work multiple jobs.

Typically you'll be asked to fill one out when you start a job. But it's a good idea to revisit it if you notice the amount withheld from your paycheck during the year is much different than what you end up owing in taxes. This could increase the size of your paycheck rather than waiting to get it back in the form of a refund.

You should also revisit it when your marital status changes, you have or adopt a child, or your employment situation changes.

The IRS has a tax withholding estimator tool that could help you decide what, if any, adjustments are appropriate to make.

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What does a W-2 form tell you?

A W-2 is the form your employer is required to send to you by the end of January documenting how much money you earned working for them in the prior year and how much tax was withheld from your paychecks. The form will also display how much money you earned from tips and any benefits you took advantage of during the year.

If you worked multiple jobs last year you should expect to receive separate W-2s from each employer.

You'll need to include each W-2 form you receive in your tax return. The form is especially important because it verifies how much you earned.

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What's a 1040 tax form?

The 1040 is the umbrella form you use to fill out your individual income tax return. In the two-page document you'll record the various kinds of income you earned last year, state whether you'll be taking the standard deduction or itemizing and report the tax credits you qualify for.

After crunching the numbers according to the instructions on the form, you'll know how much you owe in taxes or how big a refund you're due.

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Who fills out form 5695?

Form 5695 is used to declare any residential energy credits you may qualify for. If, for instance, you installed solar energy-producing roof tiles in 2022 you can claim the Residential Clean Energy Credit using the form.

Importantly, the form is not applicable to businesses.

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More of your 2022 tax season questions answered

• Tax season 2023 officially started: Here are key deadlines to keep in mind

• 1099, W-4, W-2, W-9, 1040: What are these forms used for when filing your taxes?

• What are the 2022 US federal tax brackets? What are the new 2023 tax brackets? Answers here

• 2023 tax season guide for new parents: What to know about the Child Tax Credit, EITC and more

• IRS may owe you from 2020 taxes. Here's why and what you need to do to find out if you're owed

• What is OASDI tax on my paycheck? Here's why you and your employer pay this federal tax

• Do you have to report crypto on taxes? Yes. Here's what you should know about form 8949

• What is a 1098-E form? What you need to know about the student loan interest statement

• Tax season 2023: What exactly is the mileage rate? There's more than one.

• Is it better to pay someone to do your taxes or do them yourself? We'll help you decide.

• What is income tax? What to know about how it works, different types and more

• Is Social Security income taxable by the IRS? Here's what you might owe on your benefits

• Companies can deduct full cost of business meals on 2022 tax returns

• Who has to file a tax return: It's not necessary for everyone. Here are the rules.

• What is capital gains tax in simple terms? A guide to 2023 rates, long-term vs. short-term

• Best way to receive your 2023 tax refund? IRS says direct deposit. Here's how to do it.

• What is FICA? How much you contribute to federal payroll taxes.

• How much is the Child Tax Credit for 2023? Here's what you need to know about qualifying.

• A 30% national sales tax? Abolishing the IRS? What the FairTax Act of 2023 would do.

• The Inflation Reduction Act carves out an EV tax credit for 2023. Does Tesla qualify?

Elisabeth Buchwald is a personal finance and markets correspondent for USA TODAY. You can follow her on Twitter @BuchElisabeth and sign up for our Daily Money newsletter here

This article originally appeared on USA TODAY: 1099, W-9, W-2, W-4: A guide to the tax forms and who fills them out