Phone storage holds the operating system, apps, downloads, photos, videos, and other local files. The amount you need depends on your habits more than a single rule. Someone who mainly messages, browses, and streams may use less local space than a person who records lots of video, downloads games, or keeps a large offline music library. Remember that the advertised capacity is not all available for your personal files.
Check current storage use in your phone's settings before choosing a replacement. Look at photos and videos, large apps, downloaded media, and message attachments. Cloud photo storage can reduce local use if you have a reliable connection and understand how originals are managed, but it is not a substitute for a separate backup. If your device supports removable storage, confirm which content can actually be stored there.
Choose enough room for your present use plus some growth, especially if you plan to keep the phone for years. High-resolution video and large games can consume space quickly. If two configurations differ in price, weigh that cost against your typical storage use and available backup options. A few simple habits also help: remove offline downloads you no longer need, review large attachments, and avoid keeping multiple copies of the same files.