etc., means and so on, and the others, and the rest. It is also used abbreviated "etc.", and pronounced the same as the full word, etcetera. It is used at the end of a sentence, when we list some items and we want to say that other items can also be part of the relationship. Ex: I bought a notebook, pen, pencil, eraser etc.
Etcetera when used in the abbreviated form "etc.", it is always followed by a period, and when it is at the end of a sentence, this period will act as a period. Ex: I bought grapes, pears, plums, oranges etc.
The use of the comma, after the enumeration of items and before etc., is questioned, since "etc." it means "and the others", "and the others", so the use of the comma becomes unnecessary. Some authors defend the use of the comma before etc., as it is an enumeration.
Etcetera, is a word of Latin origin (et cetera), and similarly to Portuguese, it is used abbreviated, in the English vocabulary, with a period at the end and always preceded by a comma. Ex: I like cookies, muffins, doughnuts, etc.
