These all refer to the same thing in respect of the Holy Spirit:
1. Fell (Acts 10:44)
2. Poured (Acts 10:45)
3. Indwelt (Acts 10:45)*
3. Received (Acts 10:47)
4. Baptized (Acts 11:16)
5. Given (Acts 11:17)
6. Filled (Acts 11:17)*
I put a * next to indwelt and filled. In Acts 10:45 they received the gift of the Holy Spirit. Just as those in Acts 2:4 were indwelt with the Holy Spirit at that time so too now are these Gentiles in Acts 10:45. In Acts 11:17 Peter describes it as the "same gift". Those in Acts 2:4 were filled with the Holy Spirit (cf. Acts 1:5) so too now are these Gentiles.
Mounce - Even after people are permanently filled with the Spirit at conversion, the Spirit can again fill them in a sense that he possesses and empowers them in a special way for a temporary, specific ask, such as when Peter spoke to the Sanhedrin (Acts 4:8) and the church prayed for boldness (4:31). Paul is filled with the Spirit (9:17) and almost immediately begins to testify (9:20). He is later filled with the Spirit again and denounces Elymas the magician (13:9) (Mounce's Complete Expositry Dictionary of Old and New Testament Words, fill, page 250).