Here are the matches for the definitions and words provided:

1. **We do this to turn something off.** - **d. switch off**
2. **This is when we send messages over our mobile phones.** - **f. texting**
3. **This helps keep our devices safe.** - **h. password**
4. **This has web pages and we use it when we are online.** - **a. internet**
5. **This is when we put information into a computer.** - **g. enter**
6. **We look at this on a computer or mobile phone to read information.** - **c. screen**
7. **This is a type of computer that we can hold in our hand.** - **b. tablet**
8. **This is something we download.** - **e. file**

So the list is:
1-d, 2-f, 3-h, 4-a, 5-g, 6-c, 7-b, 8-e.