Resistance Value
The targeted resistance value of the component.
Tolerance
The variation in the resistance value by manufacturing processes. 1% resistors are very common and we used these whenever possible. 0.1% is used for high precision measurement. 5% resistors are typically used when a higher power rating is required, as higher power rating and high precision can be expensive.
Power Rating (in Watts)
The power rating of a resistor is dependant on the maximum allowed temperature of the resistor (typically around 70 degrees in the datasheets). Make sure to have at least a small safety factor for the power rating. P = I2R
Package / Footprint
The physical size of the resistor. 0603 resistors are used whenever possible, as they are easy enough to hand solder and a good compromise for space saving.