> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tape.network/llms.txt
> Use this file to discover all available pages before exploring further.
# Epochs
The network runs on a clock. Time is divided into epochs (the duration is a network parameter), and everything network-wide changes at epoch boundaries, by vote. Nodes stake to join the committee, membership refreshes each epoch, and stake changes take effect over two epochs to keep turnover gentle.
Each epoch moves through four phases:
* **Sync**: spools that changed owners are transferred or recovered before serving begins.
* **Snapshot**: the previous epoch's record is finalized by group votes. The network does not advance past an epoch whose record isn't sealed ([snapshots](/protocol/architecture/tape-replay#snapshots)).
* **Active**: the bulk of the epoch. Serving reads, accepting writes, running [challenge rounds](/protocol/architecture/challenges).
* **Closing**: node preferences are aggregated by quorum-weighted vote (group count, committee size, prices), and the next epoch's spool assignment is computed and voted in ([spool groups](/protocol/architecture/spool-groups)).
This is how the network grows without hard limits. Capacity, membership, and pricing are standing votes, re-aggregated every epoch ([token economics](/protocol/architecture/token-economics) lists them all).
