Logic. [] A bistate signal, often for triggering an event or setting a state. For in ports, any signal level at or above 0.5 is treated as high logic, and anything below is assessed as low logic. Logic in ports are only sensitive to these state changes so jumping from 0 to 0.5 will register, but a slow ramp from 0.5 to 1 means nothing. For out ports, a high-logic state is expressed as 1, and a low-logic state is transmitted as 0.
For short, we may sometimes refer to a trigger, which is the transition from a low-logic state to a high-logic state. This signal is often used to start a function.

Phase. [] A unipolar signal from 0 to just below 1, often for driving data lookup. For in ports, signal are wrapped into the range. For example, a value of 1.02 would be used as 0.02, and a value of -0.3 would be treated as 0.7.

Pitch. [] A bipolar signal used by Bitwig for specifying pitch. 0 represents "middle C" (C3) with each change of +/- 0.1 representing an octave, so a typical signal range of -1 to +1 represents twenty octaves.

Untyped signal. [, most often] The most common signal type, of unspecified range and function. Inputs of mixers or filters or math modules, virtually all outputs that aren’t implementing either logic, phase, or pitch signal characteristics — they are all most often untyped and thereby follow the color set for the module they are on.
Note: Generic signal modules are normally red, with typical control modules defaulting to turquoise. So ports of either color are untyped signal ports. And when a module has multiple untyped in ports, those ports will adopt the color of an incoming patch cord.

Secondary untyped signal. [] When a module has two kinds of untyped signal in or out ports, the secondary port is shown in blue. For example, a merge module might have multiple primary in ports (using the module color) for the various signals to route and one control input (colored blue) for selecting which input is passed thru.