Does a continuous effect that turns all creatures into artifacts happen in a different layer than one that gives all artifacts an ability?

Magic's Comprehensive Rules define a seven-layer system for applying continuous effects (CR 613.1). Each layer handles a specific category of change, and effects are applied layer by layer in order, which is why the layer an effect operates in matters enormously for how interactions resolve.

An effect that changes a permanent's type — for example, turning all creatures into artifacts — applies in Layer 4 (Type-changing effects) per CR 613.1d. This layer handles changes to supertypes, card types, and subtypes.

An effect that grants an ability to all artifacts — for example, "all artifacts have lifelink" — applies in Layer 6 (Ability-adding and ability-removing effects) per CR 613.1f. This layer handles adding or removing keyword abilities, activated abilities, triggered abilities, and so on.

Because Layer 4 is applied before Layer 6, if one continuous effect makes all creatures into artifacts, and another gives all artifacts an ability, the creatures-turned-artifacts will have the granted ability when everything resolves. Concrete example: Liquimetal Coating makes target permanent an artifact (Layer 4). Skilled Animator says artifact creatures you control get +5/+5 (Layer 6 for the stat change, but the type dependency matters). If Mycosynth Lattice makes all permanents artifacts (Layer 4), then a spell granting "all artifacts have flying" (Layer 6) would give flying to every permanent on the battlefield.

This layer ordering is why the sequence is deterministic: you always know which effects establish types before abilities are added based on those types (CR 613.2 for dependency rules when effects interact more complexly).