Several Latin-derived abbreviations are commonly used in both everyday and academic English (like e.g., i.e., et al., etc.). These abbreviations do not need to be explained.
Usually, these abbreviations take a full stop, “.“, after the last letter in each abbreviated word, although some publications dispense with the periods (like eg, ie, et al, etc). Some journals put all Latin abbreviations in italics, either with or without the periods (et al., e.g., i.e., etc.). Whichever style is used, it is important that the style be used consistently throughout the text.