A Milanese mesh band is smoother, more flexible, and infinitely adjustable, while a link bracelet is more rugged, more secure, and dressier. Both are metal. The better one depends on your comfort and style priorities.
The short answer
Mesh is woven from fine metal, so it drapes softly and adjusts to almost any size. A bracelet is made of solid links and feels more substantial and secure. Choose mesh for comfort and a sleek look, and a bracelet for durability and a classic sporty feel.
Comfort
Mesh usually wins on comfort. The fine weave conforms to your wrist and has no pinch points, which is great if you have wrist hair or hate link bracelets catching skin. A well-fitted bracelet is comfortable too, but the links can pinch if sized poorly.
Adjustability
Mesh is the easiest band to size. Most use a sliding clasp, so you dial in the exact fit with no tools and no removed links. A bracelet is sized by removing links, which usually needs a tool and gives you fixed increments rather than infinite adjustment.
Style
Mesh reads sleek, minimal, and slightly dressy, pairing well with thin watches. A link bracelet reads sportier and more traditional, and it's the standard look for divers and everyday steel watches. Both are versatile, so it comes down to taste.
Durability
A solid link bracelet is tougher and holds up better to hard use. Mesh is durable for daily wear, but the fine weave can snag or deform under real abuse. For a knockabout watch, a bracelet is the safer pick.
Which should you choose?
Choose mesh for all-day comfort, easy sizing, and a clean modern look. Choose a bracelet for durability, security, and a classic sporty style. Either upgrades a watch over a basic strap, so pick the one that matches how you wear it.