Just some information for you.
What are cookies?

Cookies are small, temporary files websites store on your computer to remember your settings on their site.
What is a binary?

Binary is a numbering system with only 1 digit in two states and is used as the most fundamental language of a computer.
Binary works with bits. Bits represent a state of being either on or off. On is a 1 and off is a 0.

We start counting with one, but a computer only understands ones and zeros. Since being off, a 0 is different from being on, a 1, the computer sees each of these as separate states. Each bit, therefore, has two states - either a 0 or a 1. Must fundamentally, this is binary.

In decimal, we count from 0 to 9 and then add the tens place and continue from 10 to 99. Then we add the hundreds place and continue from 100 to 999 and so forth.

Binary starts with 0 to 1 and then adds the next place and goes from 10 to 11 (not ten and eleven). Three binary bits has eight states as seen from the following count.
State 1 - 000
State 2 - 001
State 3 - 010
State 4 - 011
State 5 - 100
State 6 - 101
State 7 - 110
State 8 - 111

Early computers used 8 bits to represent data and that became the standard for computing. 8 bits is one byte.
No, they're not Oreo® cookies. Websites store them on your computer so you don't have to resend information, redo custom configurations on a site, to remember if you are logged on to a secure site or track your browsing history. This is how advertisers can put an ad on a site that has something you recently looked at on Amazon™ and how, when filling in a form, the computer knows what you put in last time.

For the most part, they're relatively harmless and maybe annoying, but they help make your browsing a bit easier. This assumes the site using them doesn't have malicious intent. Cookies can be used to get information and track you. They can be used for malicious purposes.

No hard and fast rule exists for how to handle them. Browsers can be configured to reject cookies or ask if you want to let them be installed. This can be really annoying. You can also clear them regularly. This will erase any forms you regularly enter. It's a trade off. Check your browser's help section to see how to configure it to reject, ask or clear cookies.