Difference between Organizations.OrdererOrg.Policies and Orderer.Policies in configtx.yaml file Hyperledger Fabric - blockchain

Question

I was looking at the configtx.yaml file in the test-network of hyperledger fabric samples and trying to understand what is going on. I find that there are Policies under 'Organizations' for the orderer and each peer, but also there are policies for Orderer separately as well as there are Policies under Channel and Application.
I am very confused on what exactly are the differences between these in terms of what they are trying to specify.
Here is a few places it occurs as an example:
Organizations:
# .... .... .... omit previous code
- &OrdererOrg
# Policies defines the set of policies at this level of the config tree
# For organization policies, their canonical path is usually
# /Channel/<Application|Orderer>/<OrgName>/<PolicyName>
Policies:
Readers:
Type: Signature
Rule: "OR('OrdererMSP.member')"
Writers:
Type: Signature
Rule: "OR('OrdererMSP.member')"
Admins:
Type: Signature
Rule: "OR('OrdererMSP.admin')"
OrdererEndpoints:
- orderer.example.com:7050
And also here:
Orderer: &OrdererDefaults
# .... .... .... omit previous code
# Policies defines the set of policies at this level of the config tree
# For Orderer policies, their canonical path is
# /Channel/Orderer/<PolicyName>
Policies:
Readers:
Type: ImplicitMeta
Rule: "ANY Readers"
Writers:
Type: ImplicitMeta
Rule: "ANY Writers"
Admins:
Type: ImplicitMeta
Rule: "MAJORITY Admins"
# BlockValidation specifies what signatures must be included in the block
# from the orderer for the peer to validate it.
BlockValidation:
Type: ImplicitMeta
Rule: "ANY Writers"

Answer 1

For Organizations: Orderer is an organization. This section is the definition of an organization, the organizational identities (ref). It includes: Name, ID, where certificates locate, who can be read, who can write, who are admins of this Org.
For Orderer section: It defines how orderers work (sample config) like: Consensus type, condition generates a block, how can read/write this config