Your First SOQL Query

List<Contact> contacts = [SELECT Id, FirstName, LastName, Email FROM Contact];

1. List<Contact> contacts = [SELECT Id, FirstName, LastName, Email FROM Contact]; — SELECT lists exactly which fields to retrieve; FROM names the object. Only the fields listed here are populated on each returned record — trying to read a field you didn't select throws a runtime error.

Account acc = [SELECT Id, Name FROM Account WHERE Name = 'Acme Logistics' LIMIT 1];
System.debug(acc.Name);

1. Account acc = [SELECT Id, Name FROM Account WHERE Name = 'Acme Logistics' LIMIT 1]; — when you know a query returns exactly one record (often paired with LIMIT 1, covered soon), it can be assigned directly to a single Account variable instead of a List<Account> — but if the query actually returns zero or more than one record, this throws a runtime exception.
2. System.debug(acc.Name); — safe here, since exactly one record matched.

// Wasteful: selects every field on the object
List<Account> accounts = [SELECT FIELDS(ALL) FROM Account LIMIT 10];

// Better: select only what this code actually uses
List<Account> accounts = [SELECT Id, Name, Industry FROM Account LIMIT 10];

1. // Wasteful: selects every field on the object — the label for the anti-pattern.
2. List<Account> accounts = [SELECT FIELDS(ALL) FROM Account LIMIT 10]; — selecting unused fields costs real query performance.
3. (blank line)
4. // Better: select only what this code actually uses — the label for the good pattern.
5. List<Account> accounts = [SELECT Id, Name, Industry FROM Account LIMIT 10]; — exactly the "read it out loud" clarity habit from Module 14, applied to SOQL: a query's SELECT clause should read like a list of exactly what the code below actually needs.