how to delete container disk1 please give me good idea.

You currently have macOS High Sierra installed which means you use the APFS format for your drive. APFS divides drives into containers which are bit like partitions. All your data (among other things) are in that Container. If you would still like to reformat (erase) and reinstall then follow this guide How to reinstall macOS - Apple Support. Keep in mind all your data will be lost and it will not be recoverable (without a third party recovery utility...maybe).

Container disk1 should NOT be deleted. This container contains the EFI volume, your startup volume with all of your files (usually named Macintosh HD), the Recovery volume and the VM volume (used for storing hibernation files to restore your current session from). It's also technically impossible to delete the container unless you have mounted the internal hard drive on another Mac using Target Disk Mode.

However, you can hide the container in Disk Utility by clicking on the View icon, then selecting Show Volumes Only.

Why, and what are you trying to do? Macintosh HD is the true logical drive if you want to erase it. But if you are not booted from the Recovery HD you will not be able to delete anything because it is your startup volume.

If you want to erase the entire SSD back to its new state or to change the format to HFS+ then you need to select the out-dented entry - Apple SSD SM01...

Drive Partition and Format - El Capitan or Later

1. Boot the computer and at the chime press and hold down the Command and R keys until the Apple logo and progress bar appear.
2. Wait for the Utility Menu to appear.
3. Select Disk Utility and click on the Continue button.
4. After Disk Utility loads select the drive (out-dented entry with the mfgr.'s ID and size) from the side list.
5. Click on the Erase tab in the Disk Utility toolbar. A panel should drop down.
6. In the drop down panel set the partition scheme to GUID. Set the Format type to Mac OS Extended (Journaled.)
7. Click on the Apply button and click on the Done button when it is activated.
8. Quit Disk Utility.

Thank you for this somewhat incorrect information. An SSD can be formatted APFS or HFS+. This is a user choice based on what the user needs. How to Skip Converting to APFS When Installing macOS High Sierra. Only the installer will attempt to make an SSD use APFS, but that can be circumvented. You can format an SSD using HFS+ via Disk Utility. Given the current status of APFS, it isn't such a bad idea using HFS+. You cannot backup using Time Machine to APFS formatted SSDs. Boot Camp cannot be used on an APFS formatted SSD. And, then there is FileVault. See Can APFS be used with Time Machine, Boot Camp, and File Vault?.

Quick Tip: To take screen shots of windows press CMD + Shift + 4 and then hold down the space bar to select a window. 🙂

Also slightly inaccurate you can reformat the container from Internet Recovery mode.

Formatting an SSD as Mac OS Extended (Journaled) is kind of pointless unless you plan on installing an operating system older than macOS High Sierra. If you try to install High Sierra on a SSD formatted as Mac OS Extended (Journaled), the installer will automatically convert the drive to Apple File System (APFS).