How to play against Old Sicilian Variation? How to Win Against Sicilian Opening? Beat The Sicilian!

Every variation of the Sicilian Defense : r/chess

Sicilian Defense - A Total Guide (with White's Response)

Sicilian Defence 1.e4 c5: Second Edition - Chess Opening Games

Understanding the Sicilian

Sicilian Defense: Old Sicilian Variation - Chess Openings

Why Grandmasters Love the Sicilian Defense

Why would White play 2.a3 as their 2nd move in the Sicilian Defense? It's not an accepted opening and I see no benefits. How would you go about strategizing a reply, as

The Lazy Mans Sicilian - Valeri Bronznik & Steve Giddins

Sicilian Defense - Choosing the Right Variation for You - Chessable Blog

I'm trying to understand the Sicilian Defense - Kramnik Variation (1.e4 c5 2.Nf3 e6 3.c4). Can someone, in simple terms, explain to me why Black's response of a forceful d5 is such