Cookies are small pieces of data which a website will store in a person's browser. This basically involves storing a bit of information on that computer in order for the website to interact properly with it. Very simple web pages don't need cookies because they will look the same for every single computer regardless of who is looking at them or when they are being looked at. However, the more sophisticated and developed a website is, the more likely it is to need extra bits and pieces for it to work properly.
Cookies can vary a huge amount - both in the amount of information stored, and particularly in the duration it is stored for. A session cookie just lasts while the browser is open, and is a way of making sure the computer is able to keep track of where you've been today, and give you relevant information. A persistent cookie lasts for a longer period of time which can be set by the website, and this enables the website to e.g. recognise you next time you come to visit from the same computer.
Some people dislike cookies because they are concerned about the amount of information that is being stored. For instance, some persistent cookies keep long-term records of an individual's browsing history, and some people are worried about websites being able to keep such a long history of what someone has been doing.
Others are concerned about third-party cookies. A first-party cookie is a cookie that is created by the website you are visiting (e.g. blobs.org), and is only related to that website. A third-party cookie is when a website produces a cookie on a different person's website (e.g. when advertising on that other person's website), which enable it to track a person's footsteps around a variety of different websites. Even though there may be legitimate reasons for doing this without sharing personal information, people may be concerned about the implications for lack of privacy.
Cookies enable us to offer certain features and keep them from being abused, such as the feedback form. Blobs.org does not track your browsing behaviour or obtain any personalised information.
Almost all the cookies created by blobs.org are session cookies. This means that they will be deleted when you close the browser, or when you stop using blobs.org for a few minutes.
To avoid displaying an annoying banner at the top of every page, blobs.org stores one cookie called "evervisited" to recognise that you have visited this website at least once before. It simply includes the information "yes" and is stored on your computer to tell blobs.org that you've been here before. It includes no personal information, and can be deleted at any time. It is not a counter (i.e. it always stays at 'yes' and does not count how many times you've visited). It will last up to one year, at which point you will be reminded again with a banner at the top of blobs.org that cookies are used.