Your First Language and the Program Skeleton
A programming language is the strict-grammar bridge between human and machine; yours is Java — the shortest path to both backend (Spring) and Android. Why: fundamentals (variable, condition, loop, function) are the same across ALL languages — deeply knowing one means learning a second in weeks; shallowly knowing five works with none. When: now, and ONLY Java until Phase 6 ends — remember this rule at every moment of "maybe I should switch languages" temptation. How: you write a .java file -> javac turns it into bytecode -> the JVM runs it on any OS (Phase 0, lesson 5's chain). Where: IntelliJ IDEA, package com.groundup.city — every Phase 3 lesson's code will live there. Who: you — Java is what stands under the Android world, Spring backends, and your own Samevian.