DNS can be very overwhelming and difficult to understand at first. It is very common to need to modify or change records for businesses. Email and websites both require DNS settings to work so having a basic understanding is good for any business owner. This is just a quick rundown and not meant to provide a great amount of detail. There are far better tutorials if you want to explore the depths of DNS further.
Every website requires an A record. This is the IP address that is required for a website to load properly. Most providers have fully automated setup when you purchase web hosting but its still good to know that you need an A record setup with an IP to make your website work properly. If you are ever contacted about updating your dns a record you know you are being asked to change where your domain name goes to try and load a website. Only make this sort of change if requested from a very trusted source.
The next most common records are for email service. This gets a little more tricky so I will simply state MX records are required for any sort of email service on a domain. There can be other requirements as well such as SPF and DKIM records. Typically a text record is also required to verify the domain.
DNS email settings can get very complicated so I just want to mention them. If you need assistance with your email please feel free to reach out. Mjacobf can solve most email issues in 1 or 2 hours and offer flat rates. Contact me today if you would like assistance with any DNS related issues including email setup and deliverability issues.