OK, Josepp.

US military compensation has 2 primary components - pay and allowances. Pay, or salary if you prefer, is set on the basis of a serviceperson's rank and seniority, and is geographically uniform within these criteria. Pay is taxed, subject to Social Security and Medicare deductions, and is the figure upon which retirement is computed. Allowances vary geographically, and are not taxed or otherwise subject to deductions. There are a variety of them, but the two major ones are housing and subsistence. If a person lives in military housing and eats in the mess, they are not eligible for these - they are not taken out of pay; they are not entitled to this portion of compensation. Uniforms for enlisted people are issued without charge; there is a small (currently $26/month) uniform replacement allowance. Allowances often make up about 40% of total compensation, but are not figured into retirement. A 20-year retiree will generally get 50% of base pay, or 28% of total compensation.   

Current compensation (pay and allowances) for a married Army PFC (E-3) at Ft. Drum, NY is about $3500 per month, before standard deductions, assuming that he or she chooses to live off-post in Killeen. Out of this, he pays for rent, transportation, food for himself and family, and so forth. This is within the income limits for a family of 3 to get food stamps in New York