is a 副助詞（ふくじょし） (adverbial particle) that is used to express that something is being presented as an example, but that other things in the same category also exist. In this way, it is regularly translated as ‘such as’, ‘things like’, or ‘and so on’.
may be used after nouns, to describe that (A) is being presented as an example from within a group. Alternatively, など
can be followed by の
(B), to show that (A) is only one type of thing from the broader category, (B).
Do not throw rocks and so on in this park.
He is always badmouthing people, like his roommates.
is regularly seen in its kanji form, 等（など）
. This kanji itself has a similar meaning to ‘etc’ in English.
The kanji for 等（など）
is also used in the pluralizing suffix, ら
. Due to this, we can see that this kanji is regularly utilized to highlight something that exists as part of a larger group.
You mustn’t discard things such as bags and shoes into the river.
Those people are very noisy, don't you think.
In the first sentence, など
presents (A) as being part of a larger group of similar things. This is exactly the same thing that happens in the second sentence with ら
など is also sometimes written as なんか, and has an interchangeable meaning in many situations. However, なんか will never use the kanji form of 等（など）.