Previously, Google stripped most punctuation from queries and used a whitelist system for commonly searched terms. This could complicate things if your search query included special characters because Google did not always give the most relevant results.
Especially for programmers this update will be quite a boon. For example, from now on Google will understand the difference between == and === when you enter snippets of JavaScript code.
Straight from the horses mouth (@Google HQ): you can finally search for special characters like @ and / in Google! pic.twitter.com/Xf71Sg9dWA
— Henk van Ess (@henkvaness) January 24, 2017
H/T: Tweakers