When discussing savory ingredients, it's helpful to categorize them by their primary function and source. Here's a breakdown of the main types:
Proteins:

These provide a fundamental savory base. Examples include:

Meat (beef, poultry, pork, etc.)1
Seafood (fish, shellfish)2
Plant-based proteins (tofu, tempeh, legumes)3
Hydrolyzed vegetable and animal proteins.4

Umami Enhancers:

These ingredients boost the "savory" or "meaty" flavor.5

Monosodium glutamate (MSG)6
Yeast extracts7
Nucleotides8

Starches:

These contribute to texture and can also carry savory flavors.

Potatoes9
Grains (rice, pasta, etc.)
used also as thickeners.10

Herbs and Spices:

These add aromatic and flavor complexity.11

Examples: salt, pepper, garlic, onion, rosemary, thyme, cumin, etc.12

Fermented Products:

These often provide deep, complex savory notes.13

Soy sauce14
Miso15
Cheese16
Vinegars.

Oils and Fats:

While not always providing a strong flavor on their own, they carry and distribute savory flavors throughout a dish.

Vegetables:

Many vegetables add savory notes to dishes.17 Onions, mushrooms, and tomatoes are good examples.18

Key points to remember:
The "savory" taste is often associated with umami, one of the five basic tastes.19
Many ingredients overlap categories. For example, some cheeses are both protein sources and umami enhancers.20
The savory ingredient market is growing, with increased intrest in natural ingrediants.21