What is Apex?
Apex is an object-based development language used to operate and customize Salesforce. Apex developers write Apex code to automate workflow models and execute controls related to how Salesforce data are calculated, rendered, and transacted against custom views and processes.
Apex is a strongly typed language. This means that it directly references data objects and field names to compile. Compiler will fail if object and/or fieldname references are not correctly declared.
Apex is Java-based so it uses similar expressions, statements, variables, and looping structures. When writing Apex code, you leverage both SOQL (Salesforce Object Query Language) & SOSL (Salesforce Object Search Language) to query the database and return lists of sObject records (Salesforce data records). Salesforce DML (data manipulation language) is used to insert, update, and delete from the database.