refers to the practice where a piece of code, or a reference to a code is placed inside the internet advertisement. All internet advertisements can and almost without exception have tags. These tags are executed by the browser even when there the internet user does not see the tag.

same as tracking tag, but generally refers to using an empty gif image to create a connection between the host of the pixel and the user. 

a piece of code that is placed inside online advertisement for tracking, data collection, cookie syncing or other purposes.

is the practice where two advertising technology platforms "integrate" between each other by placing two or more tracking in the same event.

a tag that is intended to facilitate for cookie syncing, but also allows changing the delivered tag on the fly without the publisher's knowledge.

If the tag is hosted by the same party that hosts the delivered content

Is such a party that the publisher in question (e.g. cnn.com) has a direct relationship with.

Is a term not widely used within the internet advertising industry. Mistakenly all tags except 1st-party tags are referred to as 3rd-party. It is intended to reference tags that are loaded, without having a direct agreement/relationship with the publisher. A better way to explain what actually is happening (i.e. tags inside tags inside tags inside tags...) is "nth-party".

where the publisher, and often the publisher's 3rd-party partners do not have a direct relationship with the company that is hosting the tag. The greater the 'n', further away the publish is from being able to fulfill its liability with the user.