linguistic:paraphrasing
Frequency stability

Temperature changes, other environmental changes, aging, and manufacturing tolerances will cause component values to "drift" away from their designed values. Changes in frequency determining components such as the tank circuit in LC oscillators will cause the oscillation frequency to change, so for a constant frequency these components must have stable values. How stable the oscillator's frequency is to other changes in the circuit, such as changes in values of other components, gain of the amplifier, the load impedance, or the supply voltage, is mainly dependent on the Q factor ("quality factor") of the feedback filter. Since the amplitude of the output is constant due to the nonlinearity of the amplifier (see Startup section below), changes in component values cause changes in the phase shift ϕ = ∠ A β (j ω) {\displaystyle \phi \;=\;\angle A\beta (j\omega)} of the feedback loop. Since oscillation can only occur at frequencies where the phase shift is a multiple of 360°, ϕ = 360 n ∘ {\displaystyle \phi \;=\;360n^{\circ }}, shifts in component values cause the oscillation frequency ω 0 {\displaystyle \omega _{0}} to change to bring the loop phase back to 360n°. The amount of frequency change Δ ω {\displaystyle \Delta \omega } caused by a given phase change Δ ϕ {\displaystyle \Delta \phi } depends on the slope of the loop phase curve at ω 0 {\displaystyle \omega _{0}}, which is determined by the Q {\displaystyle Q}