private information may be stored in cookies on the system

Hi DeniseNT
 
In general or for the most part a cookie will contain a string of text that contains information about the browser, i.e., some information that whilst it relates to you it would not generally be termed 'personal' informaiton. And to work a cookie does not need to know who you are & where you are from; it only needs to remember your browser. 
 
In terms of more detail, these cookies are typically used for referral programs, sponsored links or adverts, for conversion and referral tracking and typically expire after 30 days, though some may take longer. Again, in the case of these and indeed most cookies, no personal information is stored, saved or collected.
 
However, some websites do use cookies to store more personal information about you, which they glean from your online activities such as user credentials entered, etc., and which, if the data held is not encrypted, could be read by other websites that you would want. 
 
This storage of data may in itself not necessarily be for nefarious reasons; it depends on how a website has set up its cookie feature. 
 
However, some websites use a combination of methods: on your browser they may create a cookie with unique but anonymous content; or on the server side they may create a file that logs that unique but anonymous content alongside any personal information that you have provided.
 
And the underlying issue is the user will not in generall know which site is doing what in terms of the above.
 
So to many the best approach is to 'ban' cookies altogether; more safety but at the expense in most case of a richer more focussed browsing experience and some limitations to site access, etc.
 
There is a middle way which is to 'ban' tracking cookies and/or 3rd party cookies but here we are getting into detail about the diffferent types of of cookies, etc...perhaps a discussion for another time.
 
Hopefully that answers your question and provides some guidance?
 
Regards, Baldrick