Photoshop Brush Option (at top):

1st item select tool
2nd item change brush shape, hardness, angel etc., click doc icon to save as preset
3rd option, brush setting panel
4th item mode: examples
Multiply: pick color, each pass, color gets darker (blacker)
Normal: each pass, stays same
Screen: lighten paint already on canvas

5th option: opacity 100% opaque vs 50% light
6th: (next to opacity) pressure sensitive pallet – pressure affects opacity
7th: flow 100% vs 40% single click vs 40% similar to opacity but if click and drag (circular) gets opaque
8th: airbrush button lets you increase flow without needing to drag cursor
9th: smooting 0 vs 37% shows fewer imperfections in stroke
10th: smoothing options (Pulled String Mode, Stroke Catch-up, Catch-up on Stroke End, Adjust for Zoom)
11 – last option is pressure sensitivity, harder press means larger brush

Right click on preset picker (option 1) to reset tools to defaults
Command + delete clears all canvas bg color
] right bracket key makes brush larger