--- title: "Fulfillment Glossary: 3PL, FBA, WMS, SKU, SLA Explained | MTP Group" description: "E-commerce fulfillment and logistics glossary: 3PL, FBA/FBO/FBS, pick-pack, WMS, SKU, SLA, cross-docking. Short, practical definitions for DTC operators." lang: en canonical: https://www.fulfillmentmtp.com.ua/en/glossary/ generated: 2026-04-24T11:34:04.102Z --- [Home](/en/) / Glossary Reference # Fulfillment & E-commerce Logistics Glossary Short, practical definitions of the 10 terms every DTC operator and 3PL buyer should know. Written for founders evaluating fulfillment partners in Ukraine and the EU. [Fulfillment](#fulfillment)[3PL (Third-Party Logistics)](#3pl)[FBA / FBO / FBS](#fba-fbo-fbs)[Pick and Pack](#pick-pack)[WMS (Warehouse Management System)](#wms)[SKU (Stock Keeping Unit)](#sku)[SLA (Service Level Agreement)](#sla)[Cross-docking](#cross-docking) ## Fulfillment The logistics layer between a customer clicking "buy" and the order arriving at their door. Includes receiving, storage, picking, packing, shipping, and returns. Outsourcing fulfillment means handing physical operations to a 3PL and paying per activity (per-order handling, per-cubic-meter storage). For brands shipping into the EU, Ukraine-based fulfillment beats German or Czech 3PLs on landed cost by 40–60%. Full breakdown in the [What is Fulfillment pillar](/en/what-is-fulfillment/). Rates — [pricing page](/en/prices/). ## 3PL (Third-Party Logistics) An external logistics provider running warehouse and shipping operations for an online store or B2B seller. The "third party" sits between the manufacturer/seller and the end customer. The PL hierarchy: 1PL — the seller self-ships; 2PL — a hired carrier; 3PL — full warehouse + shipping outsourcing; 4PL — a manager coordinating multiple 3PLs. For DTC brands entering the EU via Ukraine, a local 3PL is the baseline infrastructure. See [3PL logistics in Ukraine](/en/3pl-logistics/). ## FBA / FBO / FBS Three models for how a seller splits inventory and fulfillment with a marketplace. FBA (Fulfillment by Amazon) The original Amazon program — inventory lives on Amazon's warehouses, Amazon picks and ships. See the [FBA history on Wikipedia](https://en.wikipedia.org/wiki/Fulfillment_by_Amazon). The term is often used generically for "fulfilled by the marketplace." FBO (Fulfillment by Operator) Inventory stored and shipped by a marketplace operator or a 3PL partner. In Ukraine: Rozetka FBO, Prom.ua FBO, Kasta FBO. FBS (Fulfillment by Seller) Inventory stays at the seller's warehouse; the marketplace only routes orders; the seller picks, packs, and hands to a carrier. Works when you already have warehouse capacity. **RealFBS** — a hybrid: your 3PL (e.g. MTP Group) fulfills to marketplace standards, but shipping moves through marketplace logistics. The practical middle ground for most SMB sellers. ## Pick and Pack Picking items from warehouse bins and packing them for shipment. The primary billable event in fulfillment pricing. **Picking**: a picker works a WMS-optimized route, scans barcodes at each bin, and the system blocks mis-picks at the scanner. Modern approaches: voice-picking, pick-by-light, batch-picking (combining multiple orders in one tour). **Packing**: right-size carton selection, protective fill (bubble wrap, paper void fill), carrier label printing, inserts (invoices, thank-you cards, promo codes). MTP Group's pick accuracy runs at 99.7%. ## WMS (Warehouse Management System) Software that runs a warehouse: bin-level addressable storage, pick routing, real-time inventory, analytics. Without a WMS, a warehouse runs on the floor manager's memory — it cannot scale. With a WMS, every SKU has a bin address, every movement is barcode-scanned, and integrations push real-time stock into Shopify, WooCommerce, BigCommerce, Rozetka, Prom.ua via API or webhook. MTP Group operates a proprietary WMS with out-of-the-box connectors for all major Ukrainian marketplaces and international e-commerce platforms. ## SKU (Stock Keeping Unit) A unique identifier for one product variant. One SKU = one concrete product in one size/color/packaging. Example: a "Basic White T-shirt" available in 3 sizes × 4 colors = 12 SKUs. Each SKU tracks its own stock level, velocity, return rate. On packaging, SKUs appear as barcodes (EAN-13, Code 128, GTIN). Clean SKU hygiene is the foundation for accurate inventory, correct pick tickets, and honest ABC-XYZ analysis. ## SLA (Service Level Agreement) Contractual guarantees from the fulfillment operator: cutoff time, pick accuracy, response time, returns handling. Typical fulfillment SLAs: cutoff (when an order still ships today), pick-to-ship time, pick accuracy (%), manager response time, returns turnaround. MTP Group operates a 15:00 same-day cutoff, four daily carrier pickups, 99.7% pick accuracy, and a 15-minute response window during business hours. ## Cross-docking A logistics model where goods move directly from the inbound dock to an outbound truck without warehouse storage. Used for fast-moving categories (grocery, seasonal goods) where storage is unnecessary. Shortens lead time but demands precise inbound/outbound scheduling. For most DTC brands, classic fulfillment with storage is the right default; cross-docking is an edge case. ## Read next - [What is Fulfillment — complete guide](/en/what-is-fulfillment/) - [3PL logistics in Ukraine](/en/3pl-logistics/) - [2026 fulfillment pricing](/en/prices/) - [Online cost calculator](/en/calculator/) - [FAQ — 30+ answers](/en/faq/)