The Standard realm

Standard is the persistent realm. It never ends. When a season finishes, your character moves into Standard whole.

What moves intact

Your character, level, experience and name.
The passive tree, with one free complete respec on arrival, because Standard may use different numbers (Passive points and respec).
Spells, ranks, spell experience and glyphs, with their slots (Spell ranks, Glyphs).
Runes, socketed items and runewords. A season-only runeword keeps working on items already made but cannot be crafted in Standard unless it is added to the core list.
Atlas progress: Standing, Focus, mini-boss tiers (Standing and Tokens).
Seals, Writs, the Sigil and the flag showing you have earned all four Seals (Seals and the Sigil of the Unburied King).
Campaign progress: acts, shards and waypoints.
Inventory, equipment, depot, gold, orbs and maps.
Guild membership and ranks. Achievements, titles, outfits and mounts.

What does not move

Houses are released and the rent is returned.
Open offers are cancelled, with items and gold returned first.
Party, trade and instances are dropped.
The ladder is archived as a hall of fame.
Season-only consumables become inert trophies.

Account stash tabs become remove-only "Season N" tabs (Depot and stash).

Legacy items. Finished gear made with a season mechanic keeps its stats, and shows a Legacy line. It can never be re-rolled with the season mechanic again.

Standard's rules. Standard has no new content during a season. Its drop tables stay frozen while the season runs. It keeps its own ladder, without titles.

Why the character moves whole. Deleting a player's best item is the fastest way to lose them. Nothing is lost silently.