Independent contractor agreements are for when you need to hire someone to do something for you that isn't a core part of your business. For example, since I'm in the business of providing legal services, I couldn't hire someone as an independent contractor to provide legal services on my behalf, but I could hire someone as an independent contractor to provide office assistance, scheduling, marketing, and so on.

Independent contractors can be more flexible and aren't entitled to many of the protections that employees are, so it's very important to classify the people you hire correctly.

These agreements are for goods or services that you're obtaining from, or providing to, someone else. If your client is hiring you to provide consulting services, for example, that'll probably be reflected in a service agreement.

Similarly, if your business is using GMail or a similar platform, then GMail is your service vendor for email services. The terms you agreed to when setting up your account are a kind of vendor agreement.

Sometimes you need to allow for a relationship that's ongoing but not uniform across time. For example, if you're hiring a third-party software developer to build and maintain your app for you, you'll need an agreement that leaves flexibility for you to change priorities, set up new targets or milestones, and so on.

A master services agreement ("MSA" for short) is a way to outline the broader terms of your business relationship while also letting you use smaller, simpler Statements of Work ("SoW"s) to reflect the then-current goals and expected deliverables.

Many businesses raise funds by issuing debt or equity. While there are many ways to do this (and lots of rules about how it's done!), some of the simplest – and therefore the most common among early-stage companies – are promissory and convertible notes.

A promissory note is basically just a debt contract. It spells out who owes what to whom and on what terms. For example, "I'll owe you $10k and will repay it over the course of a year, starting a year from today, at n% interest."

A convertible note is basically a promissory note that can also be repaid with equity in the company rather than cash. For example, "I'll owe you $10k and will repay it over the course of a year, starting a year from today, at n% interest. Alternatively, a year from today, I'll give you $10k worth of my company shares."

An NDA or confidentiality agreement exists to make it safe(r) to disclose confidential information for business purposes. Sometimes a larger agreement between businesses (or between a business and an investor) will have confidentiality provisions inside it, but there are also times when you'll want a free-standing agreement for this purpose.

A very common situation is one where two businesses need to disclose some confidential information not just as part of an ongoing business relationship, but in order to decide whether or not to establish a business relationship. For example, if I were hiring a marketing agency, I might need to disclose to them otherwise-secret information about my current business in order for them to give me a price estimate.

Basically any software that you access through your web browser or that involves paying a subscription is a SaaS arrangement. This is an increasingly common way of selling software, since it has a built-in, ongoing revenue stream.

Because software provided on an as-a-service basis is an ongoing relationship, that needs to be spelled out in a contract specifically tailored for that purpose.

In trademark/copyright lingo, a "license" is a kind of permission to use something you own without giving up your ownership rights in it.

For example, I own the copyright rights in the text you're reading right now and the trademark rights in the extremely cool §-made-of-question-marks logo, but I've given Squarespace (who provides my web hosting services) a license to display them to you.

As a general rule, licenses can be very simple but you need one a lot more often than you might expect.

Influencer marketing is very common these days, but it's really important to get the details right. Part of that is about setting clear metrics and expectations. Another big part is complying with regulations about false advertising, sponsored content, and similar topics.

Whether you're hiring the influencer or you are the influencer, you'll want to make sure to dot every i and cross every t.